DOMESTIC SCIENCE 



A BOOK FOR USE IN SCHOOLS AND FOR 
GENERAL READING, 



BY 



JAMES E. TALMAGE. D. 8. D., Ph. d. 

President of Latter-day Saints' College, Salt Lake City, Utah; 
Member of American Chemical Society. 



" Till, by experience taught the mind shall learn 
That, not to know at large of things remote 
From use, obscure and subtle, but to know 
That which before us lies in daily life. 
Is the prime wisdom."— i>/t?/o«. 






\ 



m 6 1891 






PUBLISHED AT 

THE JUVENILE INSTRUCTOR OFFICE, 
Salt Lake City, Utah. 

1891. 






<: 




Copyrighted January, 1891. 



/ 



7'^ 



sy 



DEDICATORY. 

TO 
KARL G. MAESER, D. L. D., 

General Superintendent of Latter-da ij Saint 

Schools, and Pioneer Teacher 

in Such Schools; 

To whom the Author, in common with all the 
youth of this people, owes so much, this unpre- 
tentious volume is respectfully and affectionately 
inscribed. 



ENDORSKNIEKTS. 



Salt Lake City, Dec. 1, 1890. 
To All Concerned : 

With the growth of our Church school system, and 
of the Mutual Improvement Associations among our 
people, the need of text -books specially adapted for 
use under those organizations becomes very apparent. 
A short time ago, Dr. J. E. Talmage was requested 
by us to prepare a work of medium size and scope on 
subjects of practical and scientific interest ; and as a 
result he has written a small volume entitled Domestic 
Science. 

A committee appointed to examine the book has 
heartily endorsed it as a worthy work, representing an 
extended array of useful facts expressed in simple but 
forcible style, and imbued throughout with the spirit 
of our religion. 

AVe take pleasure in recommending the little work 
to our people as well adapted for use in our Church 
schools, also in the Mutual Improvement Associations, 
and for general reading. 

Your brethren in the gospel, 

WiLFORD Woodruff, 
Geo. Q. Cannon, 
Jos. F. Smith. 



Provo CiTr, Utah, Dec. 1, 1890. 

The study of Domestic Science, recognized as an 
essential feature of education, has received in this 
work by Dr. J. E, Talmage such a thorough and sys- 
tematic treatment as will entitle the work to the careful 
consideration of all educators ; I earnestly recommend 
it, therefore, to all our Church schools for adoption. 
Karl G. ]VL\eser, D. L. D., 

Gen. Supt. L. D. S. Schools. 



PREFACE. 



SEVERAL years ago, the author introduced to his 
students a brief course of instruction upon topics 
of practical, everyday interest, under the name of 
Domestic Chemistry. The class has since held a 
permanent place on his program of science teaching ; 
and he is pleased to note that with the increase in the 
number of Church schools among the Latter-day 
Saints, and with the growth of the Mutual Improve- 
ment Associations among the young people of this 
region, many other classes of the same nature have 
been established. The need of a text-book, embody- 
ing the principal facts of such a course, has been felt 
for some time ; and, in consequence, the appointment 
which led to the production of this little volume was 
made. 

The author has endeavored to bring together, in a 
simple manner, such topics as have a direct bearing 
upon the science of domestic operations. His object 
has been to direct attention to daily household affairs, 
— affairs indeed, which to many are too common to be 
deemed worthy of earnest thought. The kitchen and 
the pantry may be made a laboratory for the elucida- 
tion of many important facts of science ; and as 



11 PREFACE. 

interest is aroused in the necessary labors of the 
household, much of the unwelcome air of drudgery 
will vanish from such work. As it is plain that the 
duration of our mortal existence permits the exploration 
of but a small fraction of the domain of knowledge, 
careful judgment should be exercised in the selection 
of subjects of study ; the practical and utilitarian 
aspect of modern systems of education testifies to the 
wide recognition this fact has received among the peo- 
ple in general. 

In this book, no effort has been made to secure an 
unduly elaborate or an exhaustive treatment ; a large 
work would be poorly adapted for class use, and much 
detail might discourage the general reader in his 
study. Liberal reference has been made to the works 
of recognized authorities on the subjects treated ; in 
such cases, acknowledgment has been made in the body 
of the work. A few passages are reprints of articles 
that have appeared over the author's signature in local 

periodicals. 

J. E. T. 
Salt Lake City, Utah. 

Jan. 24, 1891. 



ANALYSIS OF CONTENTS. 



DF^jPlPS-T I. 



AIR AND VENTILATION, WITH CHAPTERS ON HEATING AND 

LIGHTING. 



CHAPTER 1. 

Some physical properties of air; impenetrability of air; pres- 
sure; air-pump, and experiments with same - - 9 

CHAPTER 2. 

Simple instruments utilizing atmospheric pressure; simple bar- 
ometer; siphon barometer; wheel barometer; aneroid 
barometer; storm glass; syringe; pumps, lifting, and 
force; pipette; siphon - - - - 21 

CHAPTER 3. 

Composition of the atmosphere ; dittusion of gases ; nitrogen ; 

oxygen; carbon-dioxide; vapor of water - - 33 

CHAPTER 4. 

Permanency of the atmosphere ; plants as agents of atmospheric 
purification ; fungi and chlorophyle-bearing plants ; mol- 
lusks and corals as removers of carbon dioxide - - 44 

CHAPTER 5. 

The air of rooms; contamination resulting from presence of 
human beings; proximity of stables, etc.; rate of con- 
tamination ; effect of lights and fires ; cellars beneath 
dwellings ------ 51 

CHAPTER 6. 

Ill effects of impure air; human respiration; foul air productive 
of scrofula; tuberculosis; tonsilitis; dysentery; effect of 
foul air on mental powers - - - - 61 



iv ANALYSIS OF CONTENTS. 

CHAPTER 7. 

Dust in the air ; effects of dust in respiratory passages ; dust- 
inhaling occupations; coal miners and tin miners; poison- 
ous dust; natural defences against dust; vibrissas and 
ciliated membranes of respiratory passages; living organ- 
isms in dust; household dust; carpets, curtains, etc., as 
dust-traps ; wall papers, arsenical papers - - 70 

CHAPTER 8. 

Ventilation: dependent on temperature changes; entering and 
outgoing currents of a room; opposite currents; mine 
ventilation; Lyman's ventilator; open fire-places as ven- 
tilators; mechanical aids to ventilation; exhaust fans; 
revolving cowls ; entering currents through windows and 
transoms - - - - - - 81 

CHAPTER 9. 

Some properties of heat: expansion of solids by heat; force ex- 
erted by expanding solids; compensation pendulums, 
gridiron, and mercurial bob ; expansion of liquids and 
gases by heat; thermometers, Fahrenheit and Celsius - 92 

CHAPTER 10. 

Communication of heat; latent and specific heat; conduction in 
solids; conductors of heat; convection in fluids; radia- 
tion of heat; latent heat and specific heat; latent heat of 
water; beneficial effects of same - - - 101 

CHAPTER 11. 

Production of heat; fuels and flame; chemical processes of com- 
bustion; moisture formed by combustion; carbon-dioxide 
formed by combustion; nature of flame; hollow condi- 
tion of flame; fuels; woods; coal; lignite; cannel coal; bit- 
uminous coal, semi-bituminous coal; anthracite coal; 
charcoal; coke; coal gas; matches - - - 109 

CHAPTER 12. 

House warming; open flreplace, ancient and modern; stoves; 
double case stove; warmed air; steam warming; warm- 
water heating; low pressure system, high pressure system 119 

CHAPTER 13. 
Light and lighting; candles; candle flame; simple lamp; Argand 

lamp; hollow wick lamp - _ - - 129 

CHAPTER 14. 

Lighting, continued; common illuminants; illuminating oils; 
flashing point and fire test of oils: coal gas, water gas, 
electric lamps,— arc and incandescent - - - 137 



ANALYSIS OF CONTENTS. 



IF'jPlK.T II. 

WATER. 



CHAPTER 15. 

Water— its occurrence;— in minerals; in plants, fresh and air 
dried; absorption of water by plants; water in animal 
bodies; in human bodies - - - - 144 

CHAPTER 16. 

Water, some of its uses and properties: as liquid, as solid, as 

vapor; freezing of water; ice crystals - - * - 151 

CHAPTER 17. 

Sources of water; rainwater; springs; hill-side springs; fissure 
springs; artesian well; equilibrium of liquids; intermittent 
springs; water of rivers; of wells - - - 156 

CHAPTER 18. 

Water— a solvent for solids; solids in natural waters; hardness 
of water; goitre prevalent in regions of hard water occur- 
rence - - - - - - - 164 

CHAPTER 19. 

Water— a solvent for gases; atmospheric gases in water; am- 
monia gas and hydrogen sulphide in water; carbon di- 
oxide in water; soda water; water in the sick-room - 171 

CHAPTER 20. 

Organic impurities in water; free ammonia and albuminoid am- 
monia in water; chlorine in water; ill effects of organic 
contamination of water; suspended matter in well water; 
living organisms in potable water - - - 176 

CHAPTER 21. 

Simple tests for purity in potable water; chemical analysis of 
water; color; clearness; odor; taste; tests for chlorine, 
and organic matters; filthy state of grave-fed waters - 183 

CHAPTER 22. 

Purification of water; boiling; distillation; filtration; domestic 
filters; Clark's process for softening water; alum and 
tannin in water; waters of Marah - - - 188 



VI ANALYSIS OF CONTENTS. 

CHAPTER 23. 

Mineral waters; sulphur waters; carbonated waters; calcium 
waters; chalybeate waters; alum waters; saline waters; 
thermal w^aters - - - - - 197 

CHAPTER 24. 

Composition of pure water; electrolysis of water; preparation 

and properties of hydrogen; oxy-hydrogen flame - 202 



r^jPLK.T III. 
FOOD AND ITS COOKERY. 



CHAPTER 25. 

Food, its nature and uses: classification of foods,— inorganic, 
organic, and auxilliary; advantages of mixed diet; condi- 
tions of digestibility; object of cooking - - - 207 

CHAPTER 26. 

Mineral ingredients of food: water, salt, lime, iron, sulphur, and 

phosphorus - - - - - - 214 

CHAPTER 27. 

Organic ingredients of food: amyloid group of food substances, 
—starch, sugar, gum; sources, preparation, and use of 
starch; sugar,— saccharine and glucose; vegetable gum - 222 

CHAPTER 28. 

Carbonaceous ingredients of food; vegetable acids— citric acid, 
tartaric acid, malic acid, oxalic acid; pectin; fats and oils 
— vegetable fats, animal fats, olein, palmitin, stearine - 230 

CHAPTER 29. 

Nitrogenous ingredients of food : albuminoids or proteids,— al- 
bumen, fibrin, gelatin, casein, gluten - - - 237 

CHAPTER 30. 

Vegetable foods and their cookery: tubers, bulbs and roots,— 
potatoes, onions, turnips, carrots, parsnips, beets, rad- 
ishes; leaves and leaf-stems,— cabbage, salads: fruits; 
seeds - - - - - - - 245 

CHAPTER! 31. 

Vegetable foods, continued: wheat— bread and bread-making; 
yeast, effect of; baking powders; new and stale bread; 
barley; rye; oats; buckwheat; rice - - - 254 



ANALYSIS OF CONTENTS. Vll 

CHAPTER 32. 

Animal foods and their cookery: use of water-bath; meats, fish, 

eggs ; seething, roasting, broiling or grilling, frying - 265 
CHAPTER 33. 
Animal foods, continued: milk, butter, artificial butters, cheese 273 

CHAPTER 34. 
Some auxilliary foods: condiments; vinegar; pickles; lemon and 
lime juices; essential oils as flavoring agents; spices; ar- 
tificial drinks— tea, cofliee, cocoa, chocolate - - 278 
CHAPTER 35. 

Preservation ol food stuffs: cause of decay: preservation by 
freezing,^ by hermetic sealing, by drying, by chemical 
antiseptics,— salt, sugar, alcohol, creosote, boric acid - 286 



CLEANSING AGENTS; AND POISONS AND THEIR ANTIDOTES. 



CHAPTER 36. 

Cleansing agents: water; soaps,— hard soaps, soft soaps, marine 
soap, Castile soap, glycerine soaps; adulterations of soap; 
aqua ammonia and other detergents - - - 293 

CHAPTER 37. 

Bleaching; explanation of process: light and air as bleaching 
agents; sun bleaching; art of bleaching as practiced in 
Holland; chlorine as a bleaching agent; bleaching pow- 
der; sulphur dioxide as bleaching agent - - 299 

CHAPTER 38. 

Disinfectants; true disinfectants, absorbents, and deodorizers; 
charcoal and lime as absorbents ; chlorine as a disinfect- 
ant; chloride of lime; sulphur dioxide; carbolic acid; 
thymol; copperas; corrosive sublimate; zinc salts; lead 
chloride; heat; instructions for disinfection - - 304 

CHAPTER 39. 

Poisons and their antidotes: nature of a poison; general treat- 
ment n\ poisoning cases; common poisons and antidotes: 
—mineral acids, organic acids, alkalies, antimony, ar- 
senic, copper, iron, lead, mercury, silver, zinc, phosphor- 
us; narcotic poisons; irritant vegetable poisons; poisonous 
meat, fish, cheese; animal venom - - - . 313 

Index - - - - - - 321 



DOMESTIC SCIENCE. 



i='jPi.:e^t I. 

AIR AND VENTILATION, WITH CHAPTERS ON HEAT- 
ING AND LIGHTING. 



CHAPTER I. 

SOME PHYSICAL PROPERTIES OF AIR. 

IT IS generally believed that the earth's surface is 
covered to a depth of several miles with a gaseous 
substance known as air or atmosphere. Owing to its 
transparency, this covering is not apparent to our powers 
of sight ; yet there are other means by which we may 
become convinced of its existence. When the air is in 
motion, it gives rise to the phenomenon of winds, 
some effects of which are familiar to all of us. The 
speed with which the moving air travels determines the 
difference between the pleasant zephyr, and the destruc- 
tive hurricane. 

The following simple oper- 
ation will conclusively prove 
the existence of the atmos- 
phere : 

Place a cork on water con - 
tained in a large bowl or bas - 
in ; take now a good sized 
glass tumbler or goblet, and 
while holding it vertically, 
with the open end down- 
ward, lower it over the float- 
ing cork, pressing down- 
ward until the glass is en- Fig. i. 
tirely submerged. As the Showing the impenetrability of 




10 



DOMESTIC SCIENCE. 



cork does not rise within the glass, we know that tlie 
water has not entered. 

Now, a ver}^ simple, yet proper question is, what 
keeps the water from lilling the inverted tumbler? 
Liquids, it is correctly said, show a tendency to seek 
their levels. There must be something inside the 
tumbler, which presses against the water, and prevents 
its entrance. Had it not been for the pressure ex- 
erted by this invisible something inside the glass, the 
water would have risen to the same height within the 
vessel as without, or until the glass was entirely filled. 
This may be made much clearer by another ex- 
periment. 

Take an ordinary lamp 
chimney, which, of course, 
is open at both ends ; and, 
while holding it in a verti- 
cal position, push the chim- 
ney into the water as was 
done with the tumbler in 
the former experiment. The 
liquid will be found to stand 
at the same level inside and 
outside the chimney. The 
water, in this case, pushed 
the air from the* open glass, 
and took its place. If the 
chimney had been previously 
filled with smoke from a bit of bin-ning rag or thick 
coarse paper, the movements of the escaping air as it 
overflowed the chimney would be clearly visible. 
The following is a very pretty illustration, suitable 




Fig. 2. 
Water expelling air 



THYSICAL PROPERTIES OF AIR. 



11 



for the lecture table, and one that can be performed by 
any body who will provide himself with a few simple 
requisites in the way of apparatus, and who will 




exercise a moderate degree of patience and persever- 
ance. 

In the figure, A represents a wide-mouth bottle, which 
should hold a pint or more. This is x^rovided 



12 DOMESTIC^ SCIENCE. 

with a tightly fitting (;ork, through which two holes 
are bored. 

B is a funnel -tube passing through one of the per- 
forations in the cork. A piece of wide glass tubing- 
could be employed, though less conveniently, instead 
of the funnel tube. 

C represents a delivery tube of glass ; this can be 
easily shaped from a piece of glass tubing of the 
required length, first softened in a lamp flame. 

D is a basin or any suitable vessel containing water, 
beneath the surface of which the delivery tube C 
terminates. 

E is an ordinary bottle, which is to be first filled 
with water, and then inverted over the end 
of the delivery tube, and there supported on any con- 
venient stand, or held in position by the experi- 
menter. 

Now, as water is poured through the funnel tube 
into the bottle, air is forced there -from and escapes 
through the delivery tube into the inverted vessel. 
It may be shown by measurement that just as much 
air is crowded out, as water is poured in. 

Thus we see that this transparent invisible air 
possesses in its own degree many of the properties of 
other heavier matter. It occupies a definite amount 
of room, and prevents other things occupying that 
space at the same time. 

The atmosphere also possesses weight. By carefully 
weighing a closed vessel filled with air, and then 
weighing it again after the air has been drawn out b}^ 
means of a pump, the weight of air has been accurately 



PHYSICAL PROPERTIES OF AIR. 13 

clctcrniined. By .such means it has been found, that a 
cubic inch of dry air at the surface of the sea weighs 
.31 grains. A hundred cubic inches wouhl weigh 
therefore 31 grains; and a cubic foot would weigli 
535.68 grains, or about 1.11 ounces. About 14.4 
cubic feet of dry aii- would be required to weigh a 
pound. 

A sitting room of ordinary size, say 14 feet long, 
12 feet wide, and 9 feet high, would contain about 
105 pounds of air; and a large room suitable for 
l^ublic assemblies, say 40 feet by 40 feet, and 18 feet 
high, would hold about a ton of air. 

These calculations apply only to air at the sea level ; 
at greater altitudes the atmosphere is less dense, so 
that fewer particles are contained in a given space. At 
the altitude of Salt Lake City, a cubic inch of dry air 
weighs only .26 grains ; a cubic foot weighs .93 ounces ; 
and 17.2 cubic feet weigh but one pound. An ex- 
ample of the weight of large masses of air may be 
made in the case of the large Tabernacle at Salt Lake 
City. This immeijse building holds 1,825,588,174 
cubic feet of air, weighing 53,069 tons. The same 
l)ulk of air at the sea level would weigh 63,388 
tons. 

It is well known that liquids exert a definite pressure 
on bodies immersed in them, A forcible demonstra- 
tion which may readily be performed by ocean voyagers 
is as follows: A stout bottle is tightly corked, and 
then attached to a long cord, weighted and thrown 
overboard, the string being paid out as fast as the 
weighted bottle sinks. After a consideral)li' depth has 
been reached, the cord is drawn in. In most cases 



14 



DOMESTIC SCIENCE. 



the cork will be foiiiid forced into the bottle through 
the great pressure of the water. If, however, the cork 
used was of the ''Tom Thumb" pattern, so that it 
could not enter, the bottle may be crushed. 

In ail analogous way the air presses upon every 
object upon which it rests. To illustrate : Completely 
till a tumbler with water ; lay over the top a piece of 
glazed note paper ; hold the latter firmly in position 
by jjlacing the palm of the hand over it, and invert 
the glass. The pressure of the air will hold the paper 
in position against the mouth of 
the tumbler after the hand has been 
removed, and in spite of the down- 
ward pressiire of the water which 
rests upon the paper. This is illus- 
trated in figure 4 . 

This illustration may be very 
prettily varied by first tying a piece 
of coarse muslin over the top of the 
tumbler. The vessel should be 
filled with water, covered with a 
piece of paper, and inverted as be- 
fore. If the paper be then carefully drawn away, the water 
is still kept within the vessel by the upward atmospheric 
pressure, which is exerted on the water within ihQ 
vessel, Avhile the bottom of the rigid tumbler receives 
the downward pressure, but does not communicate it 
to the liquid within. The upward pressure therefore 
operates without the downward pressure to counter- 
balance it. 

Another experiment should follow : 

Instead of a glass vessel use a common fruit can. 




Fig. 4. 
Upward pressure of 
the air. 



PHYSICAL PROPERTIES OF AIR. 



15 



the cover having been removed, a piece of muslin tied 
over as before, and a small hole punched in the opposite 
end, as shown in the illustration, figure 5. 

Now place the finger over the small opening ; fill the 
vessel with water, cover with a piece of glazed paper, 
and invert as before. When satisfied that the pressure 
of the air sustains the water within the can, remove 
the finger, and immediately the liquid flows out, be- 
cause the downward atmos])heric pressure is communi- 
cated to the contents of the vessel through the tiny 




Fig. 5. 
Atmospheric pressure. 

aperture, and this downward pressure together with 
the weight of the water is evidently greater than the 
upward pressure of the atmosphere alone. The latter 
is overcome, and therefore the liquid falls. 

An interesting demonstration may be made by taking 
a hard boiled egg, from which the shell has been (*arc- 
fully removed. A bottle, with a mouth sufficiently 
large to partially but not completely admit the egg is 
to be provided. Place now in the bottle a bit of 
burning paper, or hold within it by means of tongs 



16 rXJMESTIC SCIENCE. 

a ''live" coal. The effect of the heat is to expand 
the air, causing much of it to pass entirely out of the 
bottle. Now put the egg in position, like a stopper 
within the mouth. As the air within the bottle cools, 
it contracts ; the outer air in its endeavor to enter the 
bottle presses on the Ggg, and forces it inward, fre- 
(luently with a loud report. 

The expansion of air by heat may be further illustrat- 
ed in this way : 

Take a small cup, burn a bit of paper within it, or 
hold a glowing coal by tongs as in the case of the egg 
and bottle experiment, described above= The air be- 
comes heated, and expanded, and a portion is driven 
out. Now remove the lire, and press the mouth of 
the cup on the fleshy part of the arm. As contraction 
by cooling occurs, the experimenter is made aware of a 
strong, and even painful tendency of the flesh to enter 
the vessel. This is a crude illustration of the surgical 
operation of "cupping," which was in general use 
years ago. By such means, blood and other matter 
could be drawn from an affected part of the body 
without the use of the lancet. 

Many other demonstrations, no less instructive than 
impressive may be made by the aid of an Ai7' Pump. 
The essential points in the construction of this useful 
instrument will be understood by reference to the 
sketch. Figure 6 shows the complete instrument. C is 
the cylinder, within which a piston works, operated by 
the lever L. As the piston is raised, air is drawn 
fi-om the large globe or receiver on the left. The mode 
of operation will be seen by a study of flgure 7, which 
shows the air ])ump in section. A valve, r, is (connect- 



PHYSICAL PROPERTIES OF AIR. 



17 



ed with the piston, within the cylinder; a second 
valve, h, is situated at the bottom of the cylinder ; these 
valves open only in an upward direction : a tube, a, 
leads from the receiver -plate to the cylinder. As the 
tio-ht- fitting piston is raised, air passes through the 




Fig.'G. 
Air-pump. 

tube a, opens the valve h, and fills the space between 
the piston and the bottom of the cylinder. With the 
first down -stroke, the air confined within the cylinder 
becomes compressed, it forces open the piston valve, 
and escapes. In subsequent strokes more air is drawn 
through the tube a, and a globe or receiver placed 
upon the plate over the entrance to a would soon be- 
come exhausted. 



18 



DOMESTIC SCIENCE. 



As an impressive illustration of atmospheric pressure, 
place a hand glass, which is simply a hollow cylinder 
open at both ends, over the aperture in the air pump 





iliiM^M;i$^^%MM?i^^^^3y;' 



Fig. 7. 
Section of air-pump. 

plate; and cover the upper opening with the hand. 
As the air is exhausted, the hand is firmly held against 
the vessel. 

A piece of sheet rubber may be tied 
over the open glass ; as shown in fig- 
ure 8 ; as the air is drawn out, the 
rubber is forced into the jar so as 
almost entirely to cover the inside. If 
instead of the rubber, a piece of blad - 
der be tied over the jar, the air pres- 
sure from above will burst the bladder inward with a 
loud report. 




Fig. 8. 

Sheet rubber 

under pressure. 




Fig. 9. 
Magdeburg hemispberes. 



PHYSICAL PROPERTIES OF AIR. 



19 



A still more striking effect of atmospheric pressure 
is shown by the Madgeburg hemispheres. 

These are two hollow half globes, made to accurately 
fit each other at the edges. The air is exhausted from 
within by attaching the pair to the air pump ; after 
which the stop -cock is turned to prevent a re -entrance 
of air. The pressure of the atmosphere is so strong, 
that very great force is required to pull the hemispheres 
apart, (see figure 9.) The apparatus derives its 
specific name from the fact that the first experiment of 
the kind is supposed to have been made at Magdeburg 
by Otto von Guericke in 1654. It is said that he used 
hemispheres so large and effective that, after the air 
had been exhausted, twenty horses were unable to 
pull them apart. 

Take now a bottle, fill it completely with water, and 
invert it with its mouth just below the surface of water 
in a larger vessel (see figure 10). The water remains in 
the bottle, although far above the level in the outer 
vessel ; it is held there by the downward pressure of 
the air which is received on the surface of the liquid in 









Fig. 10. 
Air pressure supporting a column of water. 



20 DOMESTIC SCIENCE. 

the outer vessel, and thence transmitted to the contents 
of the bottle. It is very readily seen, that, as the 
mouth of tlie inverted bottle is below the surface of 
the water in the larger vessel, air could not enter the 
bottle from without, even if the contained water could 
be mthdrawn. This phenomenon was discussed as 
long ago as the days of Aristotle, the noted Grecian 
philosoj)her, who has been dead now about twenty- 
one centuries. He taught the people, that ^'■Nature 
dislikes a vacuum.'" By "vacuum" is meant an empty 
space, one that is devoid even of air. 



ATMOSPHERIC PRESSURE. 



21 






CHAPTER 2. 

SIMPLE INSTRUMENTS UTILIZING ATMOSPHERIC PRESSURE. 

WE may very properly ask if there is a limit to this 
supporting power of the air ; or if the atmospheric 
pressure which sustains the water in the bottle, as last 
described, would be able to hold a column of liquid of 

an indefinite height. 
This question has 
been answered by ex- 
periments which are 
not convenient for 
us to repeat. If we 
could take a tube, say 
thirty -six feet long, 
closed at one end, 
fill it with water, and 
invert it with its 
open end beneath 
the surface of water, 
the liquid would sink 
to the level of thir- 
ty-four feet, leaving 
a vacuum in the up- 
per part of the tube 
jPjg 11 for the space of two 

Air Pressure Supporting Column of feet. This fact caused 
Mercury. Galileo who lived in 

the earlier part of the seventeenth century to gravely as- 
sert : ''Nature does not dislike a vacuum beyond thirty- 



22 DOMESTIC SCIENCE. 

four feet." The true explanation evidently is that the air 
pressure is just powerful enough to support a column 
of water thirty -four feet high. If a tube be filled with 
mercury ((luicksilver), and inverted in a vessel of the 
same liquid, the column will be sustained at the level 
of thirty inches. If the tube be longer than thirty 
inches, the mercury will fall to that level, and a vacuum 
will be formed in the upper part ; this is illustrated in 
figure 11. Now mercury is 13.6 times heavier than 
water; and 34 feet, which is the height at which the 
water column was sustained, is 13.6 times 30 inches, 
which latter is the height at which the mercury column 
stood. In other words, a column of mercury 30 inches 
high, would weigh the same as a column of water of 
equal diameter 34 feet high. Here then is a very con- 
venient method of measuring the pressure of the atmo- 
^ sphere. Suppose the tube used in the experiment with 
quicksilver described above, had a cross -section of 1 
square inch ; the mercury stood 30 inches high ; there- 
fore the tube contained 30 cubic inches of the liquid ; 
and this amount of mercury is found by trial to weigh 
about 15 pounds. We may conclude, therefore, that 
the pressure of the air is equal to 15 pounds to the 
square inch. 

This statement, however, is strictly true only under 
the conditions prevailing at the sea level ; for the atmo- 
spheric pressure is found to vary greatly at different 
altitudes. The higher we proceed above the sea level, 
the less becomes the air pressure. By carefully noting 
the height at which the mercury stands in a tube ar- 
ranged as above at different stations, the relative alti- 
tudes of those places may be determined with fair ac- 



ATMOSPHERIC PRESSURE. 



23 



curacy. At a height of four miles above the sea level, 
the mercurial column would be about half its ordinary 
height, or fifteen inches, and at an elevation of twenty 
miles it is supposed the pressure would not support a 
column higher than one inch. 

At the altitude of Salt Lake City, the mean height of 
the mercurial column is 25.6 inches ; this corresponds to 
a pressure of 12.8 pounds per square inch. At this alti- 
tude the body of a man of medium size, possessing 2000 
square inches of surface, n 
would sustain a weight 
of 25,600 pounds, or over 
one and a quarter tons ; at 
the sea level such a person 
would be under a pressure 
of 30,000 pounds, or ful- 
ly a ton and a half. How- 
ever, there is air within 
the body so that this enor- 
mous pressure is equably 
balanced. 

The roof of the Latter- 
day Saints' Tabernacle at 
Salt Lake City measures 
4 2,500 square feet; the 
air pressure thereon 
amounts to 39,168 tons; 
at the sea level, with the 
mercury column at 30 
inches, such a surface would be under an atmos- 
pheric jiressure of 45,900 tons. 

Such an instrument as that alreadv described — a _ 




Fig, 12. 
Showing fluctuations of tlie 
mercurial column. . 



24 



DOMESTIC SCIENCE. 



tube of proper length filled with mercury and inverted 
in a cistern of the same liquid, is usually called a Bar- 
ometer, the term meaning "weight measurer." Many 
different forms of barometers are now in use ; the most 
accurate being the mercurial barometer similar in prin- 
ciple to the kind already described. To demonstrate 
the effect of varying air pressure on the 
barometric column, proceed as follows, 
(see figure 12) : Invert a barometer tube 
filled with mercury in a bottle of the 
same liquid. Provide a doubly perfor- 
ated cork, which tightly fits the bottle 
mouth ; insert the cork with the inverted 
tube passing through, and place a short 
tube in the other perforation. By blow- 
ing through the short tube, an increased 
pressure is exerted on the mercury with - 
in the bottle, and the column rises. By 
applying suction, some air is drawn from 
the bottle, the pressure upon the con- 
tained mercury is lessened, and the 
column falls. Thus we may see illus- 
trated within a room such barometric 
differences as exist between the mount- 
ain-top and the sea -level. 

A very good instrument is the siphon 
barometer, illustrated in figure 13. This 
consists of a glass tube of proper length, 
curved upward at the bottom so as 
to form two arms of unequal length. The short arm is 
open, the long arm closed. When the tube is filled 
with mercury and inverted, a vacuum is formed in the 



Fig. 13. 

Siphon 

barometer, 



ATMOSrilEKIC PRESSURE. 



26 



upper part of the long arm, the height of the liquid 
column depending upon the prevailing atmospheric 
pressure. The tube is permanently graduated above 
and below a point, selected near the middle of the long 
tube and marked zero (0). The height of the column 




Fig. 14. Wheel barometej- 



2(t 



DOMESTIC SCIENCE, 



is determined by reading the level of the mercury in 
the long- arm above 0, and that in short arm below 0, 
and adding the two figures. 

An interesting variation in the siphon form of bar- 
ometer is the wlieel barometer, the operation of which 
will be understood from ligure 14. Resting on the 
mercury in the short arm of the tube is a float, which 
rises and falls with the liquid. By means of a rack and 
pinion, or by a string and pulley, these movements are 
communicated to an axis upon which a needle is fixed. 
This needle moves in front of a graduated disc on which 
the different states of the weather, such as "change," 
"fair," "stormy," "rain," etc., are marked. 

Another fairly reliable instrument, and a very con- 
venient form is the so- 
called aneroid barometer, 
(figure 15), in general 
shape not unlike a watch. 
The air pressure is trans- 
mitted from a very thin 
and flexible metallic casing 
to a system of levers acting 
upon the dial finger. 

Even at a fixed station 
the barometric reading is 
seldom constant for any 
great length of time, from 
which fact we learn that 
the atmospheric pressure is 
Sudden and violent weather 
changes are usually accompanied by fluctuations in the 
barometric column. But the common belief that a de- 




Fig. 15. . 
Aneroid barometer, 

continually varying. 



ATMOSPHERIC PRESSURE. 27 

creasing pressure, as indicated by a fall in the bar- 
ometric height, is an infallible indication of approach- 
ing storms, and that a " rising barometer" is surely 
indicative of fair weather, can scarcely be relied upon. 
We have not yet mastered the true science of weather 
indications. The wind still " bloweth where he list- 
eth," irrespective of our artificial rules. Our confi- 
dence in the barometric indications should not be 
impaired on this account. That little instrument 
simply informs us of changes in atmiospheric pressure ; 
if we interpret such information to mean rain, wind, or 
fair weather, we do so of our own accord : the bar- 
ometer told us no such thing. 

There is an instrument known as the storm glass, 
now in common use. It consists of a sealed tube con- 
taining a chemical solution, in which crystals appear 
with varying profusion. It is plain that the pressure 
of the air can in no way affect the contents of the 
tube, as the latter is hermetically sealed. The author 
has made systematic observations on a number of 
the instruments, and finds them entirely unreliable 
as indicators of atmospheric pressure. The solvent 
power of the contained liquid is affected by changes 
in temperature, and the instrument has a stronger 
semblance to claim as a thermometer than as a bar- 
ometer. The "storm glass" is well designed as a 
selling aricle and as a wall ornament. 

The pressure of the atmosphere is turned to practical 
account in the construction and operation of many 
simple instruments, among which the Pump is prom- 
inent. An essential feature of the pump is illustrated 
by the common syringe. In figure 1(5, a vessel of 



28 



DOMESTIC SCIENCE. 



water is shown ; in it are inserted two cylinders, each 
provided with a tightly -fitting- piston and a convenient 
handle. In the figure on the left the piston is at the 




Fig 16. Fig. 17. 

Syringe. Lifting pi:mp. 

bottom of the cylinder ; in the right hand sketch the 
piston is partly raised, the water following it. 

The Lifting Pumji (figure 17) consists essentially of 
a barrel containing a piston, which is o"perated by 
means of a lever handle. A pipe passes from the 
pump barriel to the well. At a is placed a valve, so 
constructed asjto open only upward. Any pressure 



ATMOSPHERIC PRESSURE. 



29 



received from above tightly closes the valve. An- 
other valve, similar in action, is placed in the piston 
at b. As the piston ascends, the water follov^^s it, 
owing to the pressure being relieved within the barrel, 
while the atmosphere presses with ordinary intensity 
on the water surface in the well. The force of the in- 
flowing water is suflflcient to force open the valve a. 
As soon as the down stroke of the piston begins, how- 
ever, the pressure closes the barrel valve, while the 
water forces up the piston 
valve, and fills the space above 
the piston. This water is 
lifted to the spout at the next 
up stroke. 

As before explained, the 
atmospheric pressure at the 
sea level is about 15 pounds 
to each square inch, and this 
is sufficient to raise and sus- 
tain a column of water 34 
feet high. Under the 

most favorable circumstances 
therefore, if the full pressure 
of 15 pounds to the square 
inch were realized, water 
could not be raised by a lift- 
ing pump from a greater 
depth than 34 feet; and in 
actual practice, through im- 
perfect action of the pump, 
this theoretical efficiency is 
never attained. Lifting pumps are seldom able to 




Fig. 18. 
Force pump. 



so 



DOMESTIC SCIENCE. 



raise water more than 28 feet. This is equal to a little 
more than 12 pounds to the square inch. 

At this altitude (Salt Lake City) under exceptionally 
favorable circumstances, lifting pumps may raise water 
to a height near 22 feet; but, as a rule, 18 feet is 
considered a maximum, and 16 feet is the general 
limit of efficiency. 

If it be desired to lift water to a greater height than 





Fig. ]9. 
The dropping tube or pipette. 

this, a Force Pump must be employed. This device 
is pro^dded with a solid piston and a pair of valves ; 
one valve being set in the barrel, as in the case of 
the lifting pump, and the other being connected with 
a discharge pipe, through which the water is driven 
1>\ the down sti'okc of the piston. The limitations to 
the operation of the force pump lie in the strength of 



ATMOSPHERIC PRESSURE. 



31 



the material from which the pump is constriictetl and 
in the power applied. 

The Dropping Tube or Pipette is based on the ap- 
plication of air pressure (see figure 19). By applying 
suction at one end, while the other end is immersed in 
liquid, the tube may be filled ; the finger then being so 
placed as to close the upper opening, the liquid can be 
held in the tube and be allowed to escape as desired. 
Such tubes may easily be made from ordinary glass 
tubing (figure 20). Pipettes will be found of great 
service in many simple operations of the 
household, such as the measuring of flavoring 
extracts, medicines and the like. 




Fig. 20. 
Simple pipette. 



Fig. 21. 
The siplion. 



The Siplion consists essentially of a bent tube, with 
arms of unequal length. If the short arm be inserted 
in any liquid, and suction be applied at the end of the 
long arm, the liquid may be drawn through the tube, 
and will continue to flow after the suction has ceased 
(see figure 21). This simple device may be made of 



32 



DOMESTIC SCIENCE. 




Fig. 22. 
Siphon transferring liquid wittiout disturbing sediment. 

much practical service in the kitchen and cook-room. 
Liquids may he drawn off in a clear condition without 
disturbing bottom sediment (figure 22), or top scum 
(figure 23). Milk may be taken from the setting 
pans without disturbing the cream, by inserting the 
tube beneath the cream layer. 




Fig. 23. 
SiplHiii traiislci ring I'Kiuid without disturbing top layer. 



COMPOSITION OF AIR. 33 



CHAPTER 3. 

COMPOSITION OF THE ATMOSPHERE. 

UNTIL comparatively recent times, the atmosphere was 
supposed to be elementary in its composition, that 
is, composed of but one simple substance. Now, how- 
ever, it is known to be made up of several components 
the most plentiful ingredients being nitrogen^ oxygen^ 
carbon dioxide, and ivater. The last named substance 
exists in the form of vapor. The first two, namely, 
nitrogen and oxygen, are present in much the largest 
proportions, there being about four -fifths or 80 per 
cent, nitrogen and one -fifth or 20 per cent, oxygen. 
The carbon dioxide and the watery vapor are present 
in very small and variable quantities. In its condition 
of ordinary purity there is about one cubic inch of car- 
bon of dioxide in a cubic foot of air. 

It has been calculated that if the atmosphere 
could be compressed to a total depth of five miles, 
the vapor of water being condensed to the liquid form, 
and the atmospheric constituents being arranged in 
sejjarate strata, the relative amounts would be shown 
as follows : The water would form a sheet over the 
earth about five inches deep ; above this would be a 
layer of carbon dioxide thirteen feet in depth, then a 
stratum of oxygen nearly one mile deep, and lastly, 
one of nitrogen four miles in thickness. Such an illus- 
tration is intended for comparison only ; the constitu = 



34 



DOMESTIC SCIENCE. 



cnts of the air are not so separated ; on the contrary, 
tliere is a most intimate mixture of all ; the heavy and 
the light ingredients being mingled at the surface in 
practically the same way as at the greatest heights. 
This perfect mixing is brought about by the operation 
of that wonderful law of nature, called by man the 
"Law of the diffusion of gases." To illustrate, we 
may perform the following experiment : Let us take 
two large bottles placed mouth to mouth, (as in figure 
24), the upper one containing a very 
light gas, dry hydrogen for instance, 
and the lower one a comparatively 
heavy gas, ordinary air will answer. 
In a very short time part of the heavy 
gas will have risen into the upper 
bottle, and a portion of the light 
gas will have sunk into the vessel 
below, and the two will be uniformly 
mixed. We can easily determine that 
the air and the hydrogen have become 
mixed by separating the bottles, and 
applying a flame to the mouth of 
each ; an explosion occurs. Nei- 
ther pure hydrogen nor air is ex- 
plosive of itself, but a mixture of air 
and hydrogen explodes with vigor when a flame is ap- 
plied. Xow, air is about 14^ times heavier than hydro- 
gen ; yet the tendency toward diffusion is so strong 
that the heavy air rises and the light hydrogen sinks 
till a perfect intermixture is effected. By such a pro- 
cess of diffusion the composition of our atmosphere is 
rendered practically luiiform throughout. Air has been 




Fig. 24. 
Dillusion of gases. 



COMPOSITION OF AIR. 



35 



analyzed from mines and deep valleys, as well as from 
mountain tops ; from above the sea as well as from the 
land surface, and from the upper deeps of the atmos- 
pheric ocean as reached by balloon ascents ; yet the 
only differences thus far discovered are such as are due 
to accidental contamination ; the proportions of the 
essential ingredients being practically constant in all 
cases. 

We should learn something regarding the individual 
characteristics of each of the principal ingredients of the 
atmosphere. 

Nitrogen is the one present in greatest quantity. 
This is a colorless gas, without apjjreciable taste or 

odor. It may be prepared in a 
comparatively pure state by re- 
moving the oxygen of the air, 
and this can be done through 
combustion. 

Provide any convenient stand, 
as shown in the illustration 
(figure 25). This must be set 
in a bowl of water, so as to pro- 
ject several inches above the 
water surface. Place on the top 
of the stand a bit of phosphorus* 
about the size of a No. 3 shot. 
Light the phosphorus by touch- 
ing it with a heated wire, and 
then quickly invert over it a large wide -mouth bottle, 

* Pliosplioinis should be handled only by those who have some 
knowledge of its properties. It is intensely poisonous and very easily 
inflannnable. In fact it must be kept always under water, and even 
while being handled it must be kept covered with water to prevent its 
taking fire. The fumes of burning phosphorus are very injurious, 
and phosphorus burns in the flesh are deep and painful. 




Fig. 25. 
Preparation of nitrogen 



3(; DOMESTIC SCIENCK. 

which is, of course, tilled with air. Lower the bottle 
over the burning phosphorus so as to keep the mouth 
of the vessel sealed by the water. Dense white clouds 
appear in the bottle ; these consist in reality of a fine 
white powder formed by the union of the burning- 
phosphorus with the oxygen of the air within the jar. 
After a short time this powder dissolves in the water, 
and the bottle is found to contain about one -fifth of 
its full capacity of water, which has risen from below; 
the remaining four -fifths are o(*cupied by a colorless 
gas ; this proper tests w^U prove to be nitrogen. 

The fact that the bottle bectomes about one -fifth full 
of water is significant. As the burning phosphorus 
removed the oxygen of the enclosed air by uniting with 
it to form phosphoric acid, which was dissolved in the 
water, evidently the space formerly occupied by the 
oxygen would be left unfilled, unless the water passed 
in. As one -fifth of the space originally occupied by 
the air is found filled with water, it is clear that 
one -fifth of the original substance has been removed ; 
and this amount must have been the oxygen. The 
remaining gas, four-fifths in amount, is nitrogen. 
When the contents of the bottle have become entirely 
clear, we may place a plate of glass under the mouth 
of the vessel, remove from the bowl and invert. 

If now a burning taper or a briskly flaming splinter 
be introduced into the bottle, the flame will be im- 
mediately extinguished, thus proving the inability of 
nitrogen to support combustion. A further experiment 
has been performed, but we need not re])cat it. It is 
cruel, though it embodies a lesson. If a small ani- 
iiiial, amouse, for instance, be placed In a bottle of uitro- 



COMrOSITION OF Allf. 



o / 



geu, the little creature quickly dies with all evidences of 
suffocation. Nitrogen, then, is a passive, inert gas, 
incapable of supporting combustion or of sustaining 
life. Its chief value as an ingredient of the atmo 
sphere seems to be that of a dilutent for the more 
vigorous oxygen associated with it. 

Oxygen, the second ingredient of the atmosphere in 
point of abundance, is not so easily prepared in a 
state of purity. The removal of the nitrogen of the 
air so as to leave the oxygen is almost an impossi- 
bility. But other methods may be employed. 

Make an intimate mixture of potassium chlorate and 
manganese dioxide; place the same in a flask pro- 
vided with a delivery tube and a collecting bottle, 
connected with a pneuijiatic trough, as in figure 26, 




Fig. 26. 
Preparing oxygen. 

and apply heat to the flask. Soon a gas is delivered 
through the tube with considerable rapidity ; this gas 
is oxygen. If a lighted taper or splinter be introduced 
into the oxygen, the flame is greatly increased in bril- 
liancy. A bit of phosphorus if lighted and introduced 



38 DOMESTIC SCIENCE. 

into oxygen burns with blinding brightness. A piece 
of steel wire may be made to burn in this gas as easily 
as a shaving of wood. In demonstrating the combus- 
tion of metallic wire, a bit of wood is to be first 
fastened to the wire and lighted ; the wire then takes 
tire from the wood. An animal placed in pure oxygen 
gives signs of feverish exhilaration, and if compelled 
to breathe the gas for any great length of time the 
creature dies from excessive excitement. 

A greater chemical contrast could scarcely be found 
than that which exists between inert nitrogen and 
active oxygen. If the oxygen were taken from the air, 
men and animals would speedily die of suffocation ; if 
the air consisted of pure oxygen the tissues of our 
bodies would soon be worn out, and death would re- 
sult from the unnatural energy of the vital processes. 
In an atmosphere of undiluted oxygen a combustion 
once started would soon become universal ; the metal 
of our lire-places would burn with the fuel, and nothing- 
would escape the general conflagration but that which 
had already been burned. The fact that combustion 
is possible in the air points to the presence of oxygen ; 
the additional fact that such combustion is far less 
energetic than in pure oxygen suggests the presence of 
a diluting ingredient, such as nitrogen. 

Carbon Dioxide is itself a compound substance, 
consisting of the elements carbon and oxygen. It may 
be prepared for study by pouring a strong acid on 
marble or on sodium carbonate, and catching the es- 
cai)ing gas. A bottle is to be ])rovided with a doubly per- 
forated cork, carrying a funnel tube and a delivery pipe 
arranged as in figure 27. Into the bottle a tablespoon- 



COMPOSITION OF AIR. 



39 



fill ot marble dust, or better still, the same quantity of 
baking soda, is to be placed. A little dilute muriatic 




Fig. 27. 
Preparation of carbon dioxide. 

acid is to be poured through the funnel tube upon the 
marble dust or soda. A gas is given off with vigor, 
and may be collected as was the oxygen over the 

pneumatic trough. If a lighted 
taper be introduced into a vessel 
containing carbon dioxide, the 
flame is extinguished as speedily 
as if plunged into Avater. A 
living animal placed in the gas 
dies very speedily after a few in- 
effectual gasps for relief. This 
carbon dioxide is considerably 
heavier than air. The gas may 
be ])Oured from one vessel to 
another, as shown in figure 28. 
It may be dipped by a small 
vessel from a larger one as readily 




Fig. 28. 
Pouring carbon dioxide 

as could water 



Owing to its great weight the gas 



40 



DOMESTIC SCIENCE. 



may be collected, as illustrated in figure 27, by dis- 
placement instead of over water. The delivery tube in 
such a case is to be passed to the bottom of the col- 
lecting bottle. A lighted candle held at the mouth 
will be extinguished as soon as the vessel is filled. If 
we continue to pass the gas into a vessel after the latter 
has become full, the gas will run over as water 

would do under similar 
circumstances. True, the 
substance is transparent 
and colorless, and there- 
fore entirely invisible, but 
a candle flame held along- 
side the receiving vessel 
will reveal the overflow 
(see figure 29). 

The writer once visited 
a large vinegar -factory in 
the State of Maryland. 
The vats in which the 
mash was placed to fer- 




Fig. 29. 
Carbon dioxide overflowing. 



ment were each as large as a sitting room. These vats 
were only half filled with mash, the upper space being 
left for the gathering of the carbon dioxide which is 
given off in the process of fermentation. On the oc- 
casion of the visit referred to, a double quantity of 
mash had by mistake been pumped into one of the 
large vessels. There was, of course, no room for the 
carbon dioxide to collect, and it ran over the sides of 
the vat as fast as produced. Several workmen who 
were engaged in repairing the floor around this 
])arti(iilar vat were cjuickly cnvelo])ed in the siiffo- 



COMPOSITION OF AIR. 41 

eating gas, and died before assistance could be ren- 
dered. 

Its power of extinguishing a flame is a usual 
method for determining the presence of carbon di- 
oxide; but it will be remembered that nitrogen j)os- 
sesses the same property. A more reliable test may- 
be made as follows : 

Prepare a little dear lime water, by adding water to 
good lime and afterward filtering. Pour a little of 
this into a bottle containing carbon dioxide, and 
shake. The lime water becomes at once milky from 
the formation of insoluble lime carbonate, resulting 
from a union of the lime and the carbon dioxide. By 
exposing a dish of lime water to the atmosphere, with 
occasional shaking, after a time a turbid appearance 
is produced, indicating the presence of carbon dioxide, 
which must have existed in the air. 

Watery Vapor. The existence of vapor of water 
in the atmosphere is a fact scarcely to be wondered 
at. If a vessel of water be exposed freely to the air, 
after a short time the liquid is found to have dis- 
appeared. The particles of water have not been de- 
stroyed. They have, in fact, been lifted into the air 
by the process of evaporation, and afterward they float 
as freely as the other constituents of the atmosphere. 
A very simple proceeding will prove the presence of 
watery vapor in the air about us. 

Provide a glass of ice water for observation. See 
that the outside of the vessel is perfectly dry. Set the 
glass in a warm room, and observe. In a short time 
the outside of the glass becomes covered with drops of 
liquid looking not unlike dew. This moisture could 

3 



42 DOMESTIC SCIENCK. 

have come only from the atmosphere of the room. 
Under all circumstances water can be condensed from 
the atmosphere if the temperature be sufficiently lower- 
ed. The quantity of moisture which the air can absorb 
and hold in suspension depends largely upon the 
temperature. AVarm air has a much greater capacity 
for moisture than has cold air ; and the process of 
cooling the air results in the deposition of much of the 
water which it had held. When the air contains all 
the moisture it is capable of holding at any given tem- 
perature, it is said to be saturated. 

At the freezing point of temperature, (32° F.) the 
air is saturated with moisture when it contains 2.3 
grains of water to the cubic foot. At the ordinary 
temperature of rooms (60° F.) a cubic foot of air will 
hold 5.8 grains of moisture ; at 90° F. it will hold 14.3 
grains ; and at 100° F. it may contain 19.1 grains. In 
the cold season, therefore, the air may appear 
moist because it is near its saturation point, though in 
reality it contains at such time much less moisture than 
under conditions of greater warmth. Evidently, the 
drying power of the atmosphere will depend upon its 
capacity to take up more moisture than it already 
holds. It is customary to express the drying power 
of the atmosphere in degrees, the determination being 
made by finding the difference between the temperature 
of the air and the dew point. 

IVlien under any circumstances the air becomes 
charged with moisture beyond its i)oint of saturation, 
some form of precipitation is the result. The deposit 
may occur in the form of dew, or, if larger quantities 
of water are condensed at the time, as by a sudden 



COMPOSITION OF AIR. 43 

cooling of a heavily laden clond, the fall msLj be one 
of rain, snow, or hail, as the temperature may deter- 
mine. 

Summary. Let it be remembered then that the air 
contains four essential, constant, ingredients : — nitrogen, 
oxygen, carbon dioxide, and vapor of water; and be- 
side these certain other accidental constituents, such as 
gaseous emanations from decaying matter, the volatile 
materials of fuel, the aroma of flowers, and the like. 
The nitrogen and the oxygen form the bulk of the 
atmosphere. These are present in the proportions here 
shown : — 

BY WEIGHT. BY VOLUME. 

Nitrogen - - - 23.1 per cent. 20.9 

Oxygen - - - 76.9 " " 79.1 



100. 100 



The average quantity of water present in the at- 
mosphere is perhaps near 1 per cent., and that of carbon 
dioxide is about ,,„\f, of 1 per cent by weight. 



44 DOMESTIC SCIENCE. 



CHAPTER 4. 

PERMANENCY OF THE ATMOSPHERE. 

''PHE uniform and constant composition of tlie atmos- 
1 phere appears all the more remarkable, when we 
consider the many influences of change to which most 
of the ingredients are subject. As has been already 
seen, the nitrogen of the air is an inert constituent. 
Though mixed Avith other substances, it takes no part 
in the transformations which they so readily undergo. 
Air is taken into the lungs of men and animals, and 
though the oxygen is there exchanged for carbon diox- 
ide, the nitrogen passes out again in an unchanged 
state. In all lires, oxygen combines with the fuel, and 
thus adds to the energy of the blaze, but the nitrogen 
remains still passive and free. The oxygen and the 
carbon dioxide, however, are continually undergoing 
change by an endless series of rapid combinations and 
decompositions. Let us, then, turn our attention to 
these. 

In breathing, men and animals inhale by drawing a 
portion of air into the lungs, and after an interval they 
exhale or expel about the same quantity of gaseous 
matter, though of a composition far different from that 
taken in. Expired air contains more carbon dioxide, 
and a far lower proportion of free oxygen than does 
air before respiration. Blow through a small tube, a 
straw will answer well, into a vessel of clear lime 
water : the milky appearance before explained indicates 
the presence of carbon dioxide in the breath. This is 



PERMANE^rCY OF THE ATMOSPHERE. 45 

true of thp breath of animals as well as of human 
beings. When we strive to think of the number of 
living beings constantly breathing, and thus removing 
oxygen from the air and supplying carbon dioxide 
thereto, the causes of the permanency of the atmos- 
phere become still more perplexing. 

It would seem to us at first thought, that after a time 
all the oxygen of the air would be consumed and in its 
place would be a superabundance of the deadly carbon 
dioxide. Beside the respiration of animal bodies, there 
are many other causes by which atmospheric oxygen is 
consumed and carbon dioxide produced ; such as the 
combustions in lights and fires, the decay of organic 
matter, and all common processes of fermentation. In 
some portions of the earth, vast volumes of carbon 
dioxide are thrown into the air from volcanic fissures 
and rents, from carbonated mineral sj^rings, and the 
ke. It is calculated that over 300,000,000 tons of 
coal are annually burned in the world under present 
conditions. This alone would produce upward of 
800,000,000 tons of carbon dioxide gas. A century 

ago but ah insignificant 
fraction of this amount 
was consumed ; yet the 
composition of the atmos- 
phere seems not to have 
been altered by this im- 
mense supply. There must 
^p\^_ be some powerful influen- 
Fig. 30. ces in operation, through 

Leaves exhaling oxygen. ^ymch oxygen is restored 

to the air and carbon dioxide abstracted therefrom. 




46 DOMESTIC SCIENCE. 

An experiment on this subject was made in 17 74 by Dr. 
Priestly, an English chemist, and it has been repeatedly 
verified since that time. Each of ns may make the 
demonstration his own by proceeding as follows : 
Place some freshly -plucked green leaves in a bell 
jar or large bottle, and till the vessel so as to cover 
the leaves, with water that has been charged 
with carbon dioxide. Then invert the bottle in 
a larger vessel ^of water, as in figure 30, place 
the whole in direct sunlight, and watch results. 
Very soon, bubbles of gas are seen rising from 
the leafy surfaces ; and being lighter than the water 
these bubbles collect at the top of the bottle, the 
heavier liquid sinking to give them space. When a 
surticient quantity of gas has been collected, ^^lace a 
piece of glass beneath the mouth of the bottle, and set 
the vessel right side up. Now introduce a lighted 
candle or splinter into the gas ; the increased brilliancy 
of the flame declares the substance to be oxygen. 
The carbon dioxide with which the water was originally 
charged has disappeared in the process. It is there- 
fore clear to us, that, under the influence of sunlight, 
the leaves have absorbed the carbou dioxide, and have 
exhaled oxygen in its place. 

If compelled to re -breathe their own exhalations, 
animals would soon die for want of oxygen ; yet 
the foulest emanations of animals' lungs, the suffocat- 
ing carbon dioxide, forms the chief support of the 
plant. Under the influence of sunlight, the green 
leaves of plants, through their multitudes of tiny 
pores, draw in the carbon dioxide from the atmos- 
phere, and exhale the life-giving oxygen. Says 



PERMANENCY OF THE ATMOSPHERE. 47 

Professor Joliuson, "On a single square incli of 
the leaf of, the common lilac as many as 120,000 
(breathing pores) have been counted ; and the rapidity 
with which they act is so great that a current of air 
passing over the leaves of an actively growing plant is 
almost immediately deprived of the carbonic acid it 
contains." And again, "A common lilac tree, with a 
million of leaves, has about four hundred thousand 
millions of pores or mouths at work, sucking in 
carbonic acid; and on a single oak-tree as many as 
seven millions of leaves have been counted." 

This power of the leaves is exerted only under the in- 
fluence of sunlight, direct or diffused. The active 
principle of the leaf b)^ which the decomposition of 
carbon dioxide is effected is technically known as 
chlorophyle, a word meaning "leaf -green," and so 
used because the substance is usually of a green color, 
and by its presence imparts the prevailing hue to 
foliage. The word scarcely expresses the whole nature 
of this potent compound, for in the case of multi- 
colored leaves, as for example, the petals of flowers, 
the varied tints are apparently imparted by a substance 
identical in most respects other than color with the 
chlorophyle of green leaves. Plants that contain no 
chlorophyle, (fungi), such as the mushroom, toad-stool, 
and the like, exhibit none of the colors of the higher 
plants, and they flourish when entirely deprived of light. 
Such plants do not decompose the carbon dioxide of 
the atmosphere, but they exhale this gas, and consume 
oxygen as do animals. 

Chlorophyle -bearing plants, when deprived of light 
act somewhat similarly to the fungi, thus rather vitiat- 



48 DOMESTIC SCIENCE. 

ing than purifying" the air. In the open air, the carbon 
dioxide evolved during the hours of darkness by grow- 
ing plants would be of but slight effect upon the 
purity of the atmosphere ; but in closed spaces, as 
the rooms of houses, the result would be different ; 
and therefore it is considered injurious to sleep in 
rooms containing growing house-plants. Though 
during the bright hours these beautiful growths are 
alike pleasing in their effects upon the mind and body, 
in darkness they tend, however slightly, to increase 
the contamination which is so constant a feature of 
animal and human existence. In marshy districts, 
growing plants exert another influence of great l)enefit, 
since by the absorption of water through their roots 
they aid in drying the soil. The sun -flower and the 
E]ucalyptus tree have been used in experiments of the 
kind with very satisfactory results. 

If we have read at all aright concerning the past 
history of our earth, there was a time when the de- 
composition of carbon dioxide through the agency of 
plant life took place on a scale vastly greater than that 
of the present. In that period of the earth's growth 
which is known as the Carboniferous Age, one of the 
l)reparatory stages through which the earth passed be- 
fore it was fitted for animal life, the air was strongly 
charged with carbon dioxide. At that time, however, 
vegetation flourished on the earth with a luxuriance 
far beyond any comprehension based on present cir- 
cumstances. In that age there existed extensive forests 
of mammoth ferns, gigantic club -mosses, and huge 
trees of many strange growths. All lived by decom- 
posing the carbon dioxide of the air, fixing its carbon, 



PERMANENCY OF THE ATMOSPHERE. 49 

and returning its oxygen in the gaseous state. That 
carbon has ever since been buried deep in the stony 
fastnesses of the globe, there undergoing change until 
converted into coal. Of the importance of coal, but 
little need be said. Without it, thev^^orld could not be 
what it is to-day. Now, by burning the coal its 
carbon unites once more with oxygen to form carbon 
dioxide, and thus the air receives again the substances 
taken from it through the subtle agency of plant life 
ages ago. 

But lest the carbon dioxide should become too 
plentiful for animal welfare, the Creator has wisely 
directed other influences to operate in again removing- 
this ingredient of the atmosphere as fast as it is pro - 
duced. Go walk upon the sea beach, and there watch 
the mollusks, great and small — shell fish as we usually 
term them — living in such profusion ; observe them 
carefully, and see what they are about. The stone - 
like shell forming the creatures' home, consists 
principally of calcium carbonate : and of this substance 
two -fifths, or forty per cent., is carbon dioxide. Then 
let us sail into warmer climes, and there observe the 
myriads of coral polyps so successfullv fighting the 
battle of life with the angry breakers of their ocean 
home. The substance that we ordinarily call coral is 
indeed nothing but the shell in which the tiny 
creatures lived ; and this shell is composed mainly of 
calcium carbonate taken from the waters, and contain- 
ing the proportion of carbon dioxide already named. 
The beautiful marbles which man ever has been de- 
lighted to polish and admire, and the massive lime- 
stone pillars, buttresses of the mighty hills — are made 



50 DOMESTIC SCIENCE. 

also of calcium carbonate, holding its proportion of 
carbon dioxide imprisoned by the powerful bonds of 
chemical force. 

Upon such a plan does the Creator maintain the 
equable balance of the elements. Is it not wonderful 
that the animal in the unconscious exercise of its own 
vital processes, contributes to the support of the 
humble plant ? And the plant is not unmindful of the 
aid thus received. The field of growing corn, while- 
preparing aliment for the support of a higher life, the 
rose-bush perfecting its flowers with which to please 
the eye, adorn the home, and inspire the heart of man, 
the vine laboring to ripen its tempting clusters, eai^h, 
all are purifying the atmosphere, and preserving the 
equilibrium without which animal life would soon 
cease to exist on earth. AYhat then is independent in 
nature? The mighty oak, and the gay squirrel which 
finds food and shelter beneath the hospitable branches 
of the tree, are mutually dependent. Neither the 
animal nor the plant can say to the other, "I have no 
need of thee." Each has been prepared by its Creator 
to be a support to the other. Could any power pos- 
sessing aught less than infinite wisdom have planned 
and executed so perfect, so admirable a design? 



THE AIR OF ROOMS. 51 

CHAPTER 5. 

THE AIR OF ROOMS. 

'^PHE contaminating influences to which the atmos- 
1 phere is subject through human and animal respira- 
tion have been already referred to. The atmosphere 
of closed rooms shows the effects of such influences to 
a much greater extent than does the open air, for the 
chief reason that enclosed air possesses far less oppor- 
tunity of purifying itself. Combustion of lights and 
fires within the room, and the respiration of the in- 
mates work together in consuming oxygen and pro- 
ducing carbon dioxide. 

But this is not the only change. Large quantities of 
water, in the form of vapor, are being continually thrown 
into the air, from the lungs and the skin of living 
beings. That this is true of the lungs may be made 
clearly apparent by breathing upon any cold polished 
surface. To prove that the same statement applies to 
the skin, the following simple experiment may be 
made : Take a large dry bottle, with the mouth sufli- 
ciently wide to admit your hand. Sec that the hand 
is clean and dry, and introduce it into the bottle ; after- 
ward wrap a cloth around the wrist to seal the mouth. 
After a short time, the inside of the bottle becomes 
dimmed with moisture, which will increase till it 
gathers in drops and trickles down the sides of the 
vessel. The skin over the whole body is pierced 
with innumerable tiny openings, through which vapor 
is continually escaping, unless these pores have become 
closed through uncleanliness or disease. As a result 
of numerous experiments, it is believed that the quantity 



52 DOMESTIC SCIENCE. 

of fluid matter escaping in one day from the skin of an 
adult personis not less than from two to three pounds.* 

But this liquid excretion from the skin and the lungs 
is not i)ure water ; it is indeed strongly charged with 
the products of animal decay. By way of proof as 
to the impure nature of the liquid matters in the 
breath, proceed in this way : Take a clean dry bottle 
having a wide neck : hold it before your mouth, and 
breathe into it for some time. Then close it tight- 
ly, and set it in a warm place for an hour or so ; 
after this, remove the stopper, and apply the nose 
with critical care. A foetid odor will be experienced ; 
most probably of a convincing strength, t 

A few years ago, an experimenter caused a number 
of persons to breathe through tubes into a closed 
vessel surrounded with ice, by which means the vapor 
of the breath was condensed in considerable quantity. 
Some of this liquid was injected into the blood 
vessels of dogs and other animals. The process was 
followed in almost every case by speedy death of the 
victims with all appearances of poisoning. 

* Dr. Faraday, of well merited fame, said upon this subject: — "I 
think an individual may find a decided difference in his feelings when 
making part of a large company, from what he does when one of a 
small numher of persons, and yet the thermometer may give the same 
indication. When I am one of a large number of persons, I feel an 
oppressive sensation of closeness, notwithstanding the temperature 
may be about 60 degree or G5 degrees, which 1 do not feel in a small 
company at the same temperature, and which I cannot refer altogether 
to the absorption of oxygen, or the inhalation of carbonic acid, and 
probably depends upon the effluvia from the many present." 

tSuch putrescible matter is constantly formed in the air of inhabited 
rooms ; it settles upon the walls and furniture and its thorough re- 
moval, if indeed at all possible, is a difficult undertaking. Upon these 
ollcnsive sul)stauces lliose natural and necessary scavengers, the great- 
ly abused house flies, largely feed, and but for these useful little crea- 
tures we would be in a still worse plight. 



THE AIR OF ROOMS. 53 

Though the organs of smell are of exquisite delicacy 
in enabling us to detect the presence of foul or offensive 
matters, the sense may be easily dulled, so that we 
become oblivious to the most disgusting odors. Note 
the sickening effect which one experiences on re-enter- 
ing a close bedroom, after having been in the open air 
for a time, though perhaps the person may have occupied 
that room during the entire night with complete un- 
conciousness of its foul condition. 

It is proper that every person should seek to preserve 
the delicacy of each of his senses. No power of sen- 
sation has been implanted within the human organism 
without a definite use and purpose for the benefit of 
the possessor. It is probable that we do not compre- 
hend the full purpose of the power of smell ; yet it is 
easy to perceive how we are warned against inhaling 
many poisonous emanations, through their disagre- 
able odor. Though there are some gaseous poisons 
which are utterly devoid of odor, nearly all foetid and 
disgusting smells indicate the presence of poisonous 
matters.* 

Many serious disorders have been directly traced to 
the breathing of the foul gases arising from decaying 
matters. The close proximity of stables, cow-houses, 
pig pens, and the like is a constant menace to the in- 



tThe delicacy of the sense of smell in detecting inconceivably small 
particles of matter diffused through the air, is illustrated by the oft- 
quoted statement of Dr. Carpenter:— "A grain of musk has been kept 
freely exposed to the air of a room, of which the doors and windows 
were constantly open for a period of ten years, during all which time, 
the air though constantly changed, was completely impregnated with 
the odor of musk, and yet, at the end of that time, the particle was 
found not to have sensibly diminished in weight." 



54 DOMESTIC SCIENCE. 

mates of any house so situated. However, contami- 
nation of the air from such causes may surely be 
detected by a keen sense of smell.* 

In wet localities, quantities of the injurious carbur- 
ctted hydrogen (marsh gas) originate from the rotting 
matters in the soil, and though this gas is itself with- 
out odor yet when arising from such source it is always 
associated with ill smelling gases. 

In such localities, too, and more especially in vol- 
canic regions and in the vicinity of "sulphur springs," 
the air is rich in sulphuretted hydrogen, sometimes 
called from one of its very un -inviting sources 
"rotten -egg gas.'' It is characterized by a most 
disgusting odor, and when inhaled even in small 
quantities produces severe headaches, nausea, and 
general prostration, and in larger amounts it excites a 
stupefying effect, which may terminate fatally. This 
substance is a constituent of the gases of sewers, and 
sometimes finds its way into dwellings from defective 
drain pipes, there, by its soothing effect upon 
the inmates its presence is to their senses im- 
perceptible though its effects are positively deadly. 

Having seen that contamination of air in our dwell- 
ings is constantly taking place, it is of interest to enquire 
as to the rate at which such processes are operating. 

*"The offensive trades mentioned in tlie Tublic Health Act of 1875" 
(England) "are those of blood-boiler, bone-boiler, fell-monger, soap- 
boiler, tallow melter, tripe-boiler. The model byelaws of the local 
Government Board include in addition, those of blood-dryer, leather- 
dresser, tanner, fat-melter or fat-extractor, glue-maker, size-maker 
and gut-scraper as being trades for which regulation by sanitary 
authority is desirable."— Farkes. These occupation^ are all attended 
l)y foul odors, and such i)ursuits the sanitary authorities of England 
li ive found advisable to restrict. 



THK AIR OF ROOMS. 55 

Many attempts have been made to determine the average 
quantity of air vitiated by the respiration of a single 
person during a specified length of time; but the re- 
sults are widely different owing to the varying rapidity 
of the breathing act, and the absence of uniformity in 
lung capacity. 

We may safely say, as the result of numerous and 
elaborate experiments that an adult person of average 
size in a state of restordinarilly expires 0.6 cubic foot of 
carbon dioxide per hour. The amount of this gas 
naturally present in the outer air is found by analysis 
to be about 0.04 per cent., or 0.4 parts per thousand. 
From the experimental labors of Dr. Chammont and 
others, we learn that a disagreeable smell is perceptible 
in the air of rooms as soon as the carbon dioxide has 
reached 0.06 per cent, or 0.6 parts per thousand.* 
This amount, which is 0.2 j^arts per thousand above 
that contained in pure air is considered by reliable 
authorities as the maximum quantity to be tolerated in 
the air of inhabited rooms. 

Suppose an adult person to be confined in an air- 
tight enclosure containing 3000 cubic feet of space. 
In an hour he would give to the enclosed air 0.6 cubic 
foot of carbon dioxide ; this added to the amount of the 
gas present in pure air would make the total quantity 
1.8 cubic feet, thus: — 0.6 -f (0.4 X 3 = 12) = 1.8. 

*Tlie bad smell here referred to is not due to tlie carbon dioxide it- 
self, this being an odorless gas, but arises from the foul organic matters 
of the expired air, and these contaminating ingredients increase in 
l)roportion to the carbon dioxide. As no strictly accurate methods of 
determining the amount of such putrescible substances have been 
devised, it is a rule with chemists to determine the carbon dioxide in 
*ihe air under examination, and then to estimate the amount of organic 
matter from this result. 



56 DOMESTIC SCIENCE. 

This being distributed among 3000 cubic feet would 
represent 1.8-^-3=0.6 cubic footper thousand, and here 
we see the permissable limit is exactly reached. In order 
to keep the air within this limit of impurity, during a 
second hour 3000 cubic feet of fresh air should be 
admitted to replace the contaminated air of the chamber. 
From such deductions as these, it is stated by many 
authorities that, to be properly ventilated a dwelling 
house should receive 3000 cubic feet of fresh air per 
hour for each of its inmates. This amount may seem 
excessive ; yet in determining it, no allowance has been 
made for the many contaminating influences beside the 
exhalations of the occupants. Dr. Billings places the 
requisite supply of air at one cubic foot per second, o» 
3600 cubic feet per hour. 

If fires and lights are burning in the rooms, additional 
allowance in the supply of fresh air should be made. 
It is not possible to make an accurate measurement of 
each of the many sources of contamination, it is 
necessary, therefore, to make liberal allowance for di- 
ficiencies in providing for the air supply of houses. 
The more closely we can cause the air within doors to 
approach in composition the atmosphere without, the 
more beneficial will be its effect upon health. Children 
expire a lower proportion of carbon dioxide, than do 
adults. Persons engaged in physical exertion exhale 
much more than the ordinary amount; sick people re- 
quire a greater supply of fresh air than is indispens- 
able to the healthy. It is therefore plain to us that 
buildings used for different purposes require varying 
allowances for the proper supply of air. 

At the rate of contamination already stated, the air 



THE AIR OF ROOMS. 57 

ill an ordinary bedroom, say 12 by 14 by 11 feet, con- 
taining 1848 cubic feet of space, would be contaminated 
by the exhalations of a single occupant in a little less 
than 37 minutes. A school room 28 by 35 by 14 feet 
would contain 13,720 cubic feet of air. Suppose such 
a room to be occupied by 60 children, allowing each of 
them only 2000 cubic feet of air per hour, the contained 
atmosphere would become vitiated in less than 7 
minutes. 

Fortunately for most of us, the doors and windows 
of ordinary dwellings are seldom made to close 
tightly ; consequently they permit some passage of air, 
and the evil results of neglect in ventilation ai-e delayed 
beyond the theoretical indications. 

The amount of space necessary to the well being of 
the inmates of a room is a subject requiring attention. 
If the space be made inadequately small, the entrance 
of a proper amount of air within a given time may cause 
injurious draught. * 

The figures already given as indicating the necessary 
supply of fresh air are based upon the investigations 
of many leading authorities. On this subject however 
there is a wide discrepancy of opinion, and some writers 

*Parkes has furnished us the following good illustration. For in- 
stance, suppose in a dormitory occupied by 10 persons the amount of 
space per head is only 300 feet ; to supply 3000 cubic feet of fresh air 
per hour, 30,000 cubic feet must be admitted in this period, and the air 
of the room will be completely changed 10 times, a proceeding which 
would cause in cold weather unless the entering air was warm, a most 
disagreeable draught, for the cold air could not be properly distributed 
before reaching the persons of the occupants. But if the cubic space 
per head be lOOO cubic feet, then the air of the dormitory need be 
changed only 3 times per hour, and if such renewal is effected steadily 
and gradually, the cold entering air is broken up, and mixing with the 
warm air of the apartment creates no draught." The same author has 



5S r)OMtestic sOifiNcE. 

give figures whicli by comparison would seem dispro- 
portionately low. 

Among builders there is a woeful lack of uniformity 
in ideas as to the requisite air su^Dpl}' for health. The 
writer has applied to a number of prominent architects 
for such information, some answers obtained indicated a 
belief in the figures above quoted ; others gave very 
low estimates. One architect considered necessary 
16.6 cubic feet per minute, and one gave 4 cubic feet 
per minute as a liberal estimate, adding that 4.5 cubic 
feet would be an exceptionally good. Chemical 
analysis would show the air of occupied rooms so 
supplied, to be truly filthy, and buildings so constructed 
are far from healthful. 

It is well to set our ideal conditions of atmospheric 
purity fairly high, and then approach them as closely a 
the prevailing conditions may permit. 

Another prolific source of contamination to the air of 
dwellings arises from the hurtful custom of digging 
cellars beneath the floors of houses. Cellars are usually 
damp and musty, even if nothing be stored in them ; 
but such places are commonly made receptacles for the 
most perishable of organic products. The foul gases 



<lrawii attention to the necessity of providing adequate floor space for 
eacli individual "for," says he, "if the height of the room is much over 
12 feet, excess in this tlirection does not compensate for deficiency in 
liie other dimensions although the total cubic space may be the same: 
thus it would not be the same thing to allow a man 50 square feet of 
floor space in a room 20 feet high, as to allow him 100 s(iuare feet of 
floor space in a room 10 feet high although the amount of cubic space 
allotted in each case would be identical . The reason is that the or- 
ganic matters of respiration are not equally diffused throughout the 
air of the apartment, but tend to accumulate in the lower strata, con- 
sequently excessive height does not, in their case, mean a correspond- 
ing dilution." .- - - 



THE AIR OF ROOMS. 59 

generated from such decaying matter rise into the rooms 
above, carrying with thein the influences of destruc- 
tion. The earth itself, near the surface, is rich in de- 
composable matters, and under the most favorable of 
circumstances the ground upon which a house rests 
becomes saturated with the emanations of rotting con- 
tents of the soil. Even upper rooms, though they 
may be properly plastered and floored, soon become 
foul if not thoroughly aired at short intervals. This 
is because there are many putresible substances, in the 
earth and upon the walls and furniture of the room, 
and the products of decomposition accumulate with 
alarming rapidity, unless adequate provisions be made 
for their removal. 

If the combustion of fuel in open fireplaces and in 
stoves were thoroughly accomplished, the vitiated air 
would beremoved from the room through the draught 
flue. In the case of artificial lights, however, such as 
candles, lamps and gas flames, the products of com- 
bustion, together with the nitrogen gas which is left 
after the consumption of the oxygen remain in the 
room. The rate of such vitiating processes depends, 
of course, upon the substances burned and the rapidity 
of the combustion. By careful trials it has been found 
that a pound of good charcoal requires for its complete 
combustion 11 pounds of air, which amount of air 
would measure about 150 cubic feet. One pound of 
mineral coal of ordinary quality requires a little more 
than 9^ pounds, or about 120 cubic feet of air. ■ A 
pound of dry wood consumes while burning about 6 
pounds, or 78 cubic feet of air. 

For purposes of illumination candles are but little 



60 DOMESTIC SCIENCE. 

used ; their former place is now taken by oil lamps and 
gas flames. Kerosene lamps vary greatly in the rela- 
tive amount of oil which they consume. A lamp of 
ordinary size will vitiate to an unbreathable state be- 
tween 70 and 80 cubic feet of air per hour. 

A consideration of these facts will indicate the abso- 
lute necessity of providing efficient means for a con- 
stant supply of fresh air in dwellings. 



ILL EFFECTS OF IMPURE AIR. 61 



CHAPTER 6. 

ILL EFFECTS OF IMPURE AIR. 

''PHE physical operations of which the breathing 
1 process consists, are simple. Gaseous matter is 
taken into the lungs, and after a short time much of it 
is expelled again. This ingoing and outgoing action 
might be in some degree imitated by a pair of bellows ; 
here, however, the analogy ends ; the air escapes from 
the bellows unchanged in composition or general prop- 
erties, but the air exhaled from the lungs is very dif- 
ferent from that taken in. 

Let us consider briefly the structure of the respira- 
tory apparatus. A sketch of the principal organs is 
given in figure 3 1 . The mouth is connected directly 
with a tube known as the trachea or windpipe d ; this 
extends downward through the neck into the chest 
cavity, and there divides, sending a branch (called a 
bronchus) e, to each lung. The human lung, like 
every other part of the body, is of strange and wonder- 
ful workmanship; yet simple and surprisingly efficient. 
The lung, when divested of its delicate wrappings, 
may be compared to a bag surrounding the bronchus 
(as at/), so as to appear as an expansion of this tube. 
By dissecting away the outer portions of the lung, the 
tube which enters it is seen to divide, and the branches 
subdivide again and again, as at g, till they form a 
network of tiny tubes, so minute that with our un- 
aided vision we cannot follow them to their termina- 
tions. Calling the microscope to our aid, however, we 



fi2 



DOMESTIC SCIENCE. 




Fig. 31. 
Organs of respiration. 



will find that the finest division of the bronchial tubes 
terminate in expanded bladder-like enclosures, as in 
B. These are called air vesicles, and are clustered 
together in forms suggesting bunches of grapes. A 
larger view of the air vesicles is given at C. 

During the process of inhalation air is drawn through 
the windpii)e into the lungs, there filling and inflating 
the air vesicles. The walls of these vesicles are sur- 
prisingly thin, far more delicate in structure than the 
finest of artificial fabrics. Tiny arteries and veins 
convey the blood to and from these air vesicles, the 



rr.L EFFECTS OF IMPURE AIR. ('.,'] 

vessels spreading over the surface of the vesicles, so 
that the contained blood is separated from the air only 
by the thin membranous wall already described. There 
is a remarkable tendency possessed by all fluids by 
which they strive to mix with each other, even if separ- 
ated by a tolerably thick partition, providing, of course, 
that the separating medium is at all permeable. 

By this property the air that has been drawn into the 
vesicles passes through the enclosing wall and mingles 
with the blood, and at the same time the foul gases, 
which have been acquired by the blood in its passage 
through the system, pass into the cavities of the air 
vesicles and are expelled from the body in the succeed- 
ing exhalations. In this way the blood becomes 
aerated or purified by exchanging the gaseous products 
of disassimilatiou for invigorating oxygen. Charged 
with this life-giving ingredient, the blood again goes 
bounding through the body carrying vitality and energy 
to every part. If the effete matters resulting from the 
vital processes v^ere left to accumulate within the body, 
speedy suffocation would result. They can be re- 
moved only by eflScient respiration, taking place 
through the instrumentality of comparatively pure air. 

The morbid effects wrought upon the system through 
the inhalation of impure or vitiated air are very varied. 
Many specific diseases and much general debility and 
predisposition to bodily disorders have been directly 
traced to this cause. Scrofulous affections are fre- 
quently aided in this way. This class of ills bear evi- 
dences of impaired and inefficient nutrition ; by this is 
meant the inability of the body to properly assimilate 
the elements of food and to produce therefrom heal-thy 



64 DOMESTIC SCIENCE. 

tissue. M. Baudoloque, a French physician of high 
repute and a specialist in scrofulous disorders, writes : 
' ' Invariably it will be found on examination that a 
truly scrofulous disease is caused by a vitiated air, and 
it is not always necessary that there should have been 
a prolonged stay in such an atmosphere. Often a few 
hours each day is sufficient, and it is thus that persons 
may live in the most healthy (healthful) country, pass 
the greater part of the day in the open air, and yet be- 
come scrofulous, because of sleeping in a confined 
place, where the air has not been renewed.'' 

Consumption, another dread disease, which by its 
stealthy advances carries so many of God's children 
from their homes on the earth's beautiful surface to 
their graves beneath, is closely allied in its nature to 
scrofula.* In consumption, or tuberculosis, as phy- 
sicians term the disorder, the lungs of the sufferer 
develop throughout their tissue, numerous lumpy con- 
cretions or tubercles, which consist for the most part 
of albumen in a coagulated and partially organized 
form. 

A special variety of sore throat, tonsilitis^ is 



* " One not very strong or unable powerfully to resist conditions 
unfavorable to health and with a predisposition to lung disease, will 
be sure, sooner or later, by partial lung starvation and blood poisoning 
to develop pulmonary consumption. The lack of what is so abundant 
and so cheap— good pure air— is unquestionably the one great cause of 
this terrible disease." Black, in "Ten Laws of Health." 

"A great amount of phthisis (consumption) has prevailed in the 
most varied stations of the (.English) army, and in the most beautiful 
climates— in Gibraltar, Malta, Ionia, Jamaica, Trinidad, Bermuda — in 
all of which places the only common condition was the vitiated atmo- 
ephere which our barrack system everywhere produced. And, as if to 
clinch the argument, there has been of late years a most decided de- 
cline in phthisis in these stations, while the only circumstance which 



ILL EFFECTS OF IMPURE AIR. 65 

recognized by the medical profession as frequently 
resulting from the breathing of air laden with the i^ro- 
ducts of organic decay. As this disease is of common 
occurrence among the inmates of houses that are pro - 
vided with poorly arranged drains, causing a flow of 
impure gases from the sewer or cess -pool to the rooms 
of the house, the disorder is frequently called ' ' sewer air 
throat." "It is marked," says Dr. Parkes, of London, 
' ' by great inflammatory swelling of the tonsils, very foul 
tongue, gastric derangement, accompanied by severe 
headache and intense depression. The temperature of 
the body is often not much raised, certainly not to a 
height proportionate to the severe symptoms i, but this 
low temperature, together with the intense prostration, 
are characteristic of most illnesses resulting from the 
entrance of sewer -polluted air or water into the 
system." 

Severe dysentery is frequently caused by the breath- 
ing of contaminated air. To this is to be attributed 
the periodical occurrence of summer disorders of this 
class, which sometimes result in an alarming degree of 
mortality ; especially marked are these fatal results 
among children, whose comparatively feeble vitality 

lias notably changed in the time has been the condition of the air."— 
Report of English Army Sanitary Commissioners (quoted by BLACK). 

" Carmichael, in his work on ' Scrofula,' gives some most striking in- 
stances where impure air, bad diet and deficient exercise concurred 
together to produce a most formidable mortality from phthisis. In one 
instance in the Dublin House of Industry, where scrofula was formerly 
so common as to be thought contagious, there Avere, in one ward, 60 
feet long by 18 feet wide, 38 beds, each containing four children; the 
atmosphere was so bad that in the morning the air of the ward was un- 
endurable. In some of the schools examined by Carmichael the diet 
was excellent, and the only causes for the excessive phthisis were the 
foul air and the want of exercise."— Dr. Parkes, London. 



66 DOMESTIC SCIENCE. 

and tender constitution can but poorly withstand the 
death -dealing influences of these foul causes. It is re- 
ported by travelers that the Esquimaux, the inhabitants 
of Iceland, seem oblivious to the importance of venti- 
lation in their snow huts. Warmth they crave, and 
this they may secure, though frequently at the expense 
of life. Dr. Youmans remarks, " We are therefore 
not surprised that in the foul and stifling air of Ice- 
land habitations, two out of three of all the children 
should die before twelve days old."* 

Beside the few specific bodily troubles named above, 
out of the many that could be enumerated as resulting 
from the inhalation of polluted air, the same cause 
l^roduces a general undermining of the vital powers, 
and a strong predisposition of the bodily tissues to 
disease of many kinds. All influences that tend to 
lower the bodily vitality, weaken our hold on life by 
inviting disease to take up its abode within our bodies.! 

An impoverished system is a fertile field for the ger- 
mination and development of disease germs. It is bc- 

* " The extreme cold of the winter in Iceland, reduces the system of 
domestic ventilation in that country to very primitive principles. A 
traveler there was so choked one night by the close atmosphere of the 
air-tight little chamber in which he slept with all the male members 
of the family, as to be compelled to wake his host, who sprang out of 
l)ed at the call, pulled a cork from a knot-hole in the wall for a few 
minutes, and after replacing the cork, with a shiver returned to bed." 

Science, 1889, 

t"On the imagination of mothers, educated as well as ignorant, the 
feeling still seems to be stereotyped, that the free, pure, unadulterated 
air of heaven falls upon the brow of infancy as the poppies of eternal 
sleep, and enters the lungs and circulates as a deadly poison; and still 
the shawls and blankets, sleeping and awake; are pretty generally 
employed to deprive the objects of the most rapturous, paternal 
solicitude of what was originally breathed into the nostrils of the 
great archetype of the human race as the 'breath of life.' " 

((juoted by Youmans.' 



ILL EFFECTS OF IMPURE AIR. 67 

lieved that such germs are widely distributed through 
the atmosphere, ever ready to enter the human body, 
yet they flourish within the system only when they find 
there proper nutriment, such as the impurities attend- 
ing degenerated tissues and disorganized functions ; 
otherwise they die through lack of nourishment.* 

The mental powers are greatly weakened and conse- 
quently hindered in their proper exersise if foul air be 
breathed. This would be naturally expected from a 
consideration of the close relationship existing between 
the mental and the physical functions of the body. The 
brain is appropriately spoken of as the organ or seat 
of the mind, that is to say, though the brain and the 
mind are in no sense identical, the latter is dependent 
for its action upon the former, just as the hand in 
writing is dependent upon the pen. However, the 
exact relationshij) between brain and mind are but lit- 
tle comprehended, yet it is known as a fact that an 
injury to the brain- affects in some degree the mental 
faculties, and that a strong, well-trained mind is al- 
ways associated with a properly developed brain. 

The brain is composed of nervous tissue, and is 

* "It was in England that the solution of the great problem of hy- 
giene was first attempted. ' Preventive Medicine ' it is there called. 
Palmerston told a deputation which waited on him in order to ask him 
to order a fast on the approach of the second epidemic of cholera, to 
cleanse their sewers and diligently visit the dwellings of the poor. 
And he did not confine himself to good advice, but with his usual 
energy he laid his hand on sanitary legislation, and purified the air of 
London and the large manufacturing towns. The result of the sani- 
tary measures carried out was a reduction of the mortality of London 
from 26 to 23 per 1,000, and in some of the towns to 17 per 1,000— a low 
death rate previously only equalled in the Isle of Wight. More than 
4,000 lives have been preserved yearly in London, and assuming that 
the mortality among the sick is l in 20, this number represents a dim- 
inution in yearly sickness to the extent of 80,000." Dr. Seegen. 



68 DOMESTIC SCIENCE. 

uourished by the blood in the same manner as are all 
other parts of the body. A very large proportion of 
the blood of the body passes to the brain and is dis- 
tributed over its surface through numerous minute 
vessels. As a consequence the brain is rapidly and 
strongly influenced by the state of purity in the blood, 
and as before seen, the blood is greatly affected by the 
condition of the air employed in respiration. It is 
clear then that the brain depends largely for its normal 
action upon the air that is breathed. 

Yet how oblivious are the majority of people to 
these vital facts ! Even among the noble class of 
students, old and young, all of whom are supposed to 
be thinkers, there prevails the most deplorable 
ignorance, or, if not this then the most hurtful, almost 
criminal negligence. The pupil at his books, the 
editor with his pen, the artist at his easel, and even 
the theologian asking for Divine inspiration in his 
sacred studies, are apt to voluntarilly surround them- 
selves with the stifling, mephitic atmosphere of close - 
shut rooms. Unto them the air of heaven is for- 
bidden to come. 

In places for public gatherings the conditions are 
even worse. Though architects have now partly 
learned the lesson of providing adequate avenues for 
ventilation, the thoughtless janitor persistently ignores 
the means supplied. Even in the churches and meet- 
ing houses dedicated for worship of the Being who 
framed the laws of health and who provided the means 
for their observance, places in which multitudes gather 
with the professed desire of hearing and understand- 
ing the word of God, the vitiated air begets dullness of 



ILL EFFECTS OF IMPURE AIR. 69 

intellect and torpor of spirit, and the gentle voice of 
Divine inspiration is unheeded and unheard. Much of 
the proverbial drowsiness among the congregations of 
churches is directly traceable to the closed windows 
and shut doors of those sacred edifices. Is it other 
than a grievous sin, a mockery indeed of the Creator's 
goodness, to petition for the inspiration of His Spirit, 
and then to willfully bedim our minds and bring obliv- 
ion upon our souls? The writer has been at night in 
places of worship where the lamps burned dimly for 
want of supporting oxygen ; think you the spirits of 
those present were not correspondingly darkened? Is 
Godliness to be attained^in the midst of willful and per- 
sistent uncleanliuess? 



DOMESTIC SCIENCE. 



CHAPTER 7. 

DUST IN THE Alli. 

THE principal gaseous and liquid impurities of the 
atmosphere have been dwelt upon in a previous 
chapter, but in addition to the contaminating sub- 
stances there named, there are others, consisting of 
finely divided, solid particles. The name commonly 
applied to this class of impurities is dust. Until 
recently, but little thought was bestowed upon the 
ill effects of these floating particles ; of late, however, 
the subject has received greater attention. It has been 
conclusively proved by experiment and observation 
that the inhalation of dust- laden air is a potent factor 
in the production and growth of certain disorders of 
the respiratory organs, among which bronchitis, pneu- 
monia and phthisis are prominent. 

The presence of dust within the respiratory passages 
will invariably produce serious results, owing to the 
irritating effect of hard particles upon the delicate lung 
tissues. An attentive review of statistics representing 
the comparative mortality among people of different 
dusty occupations, reveals the fact that the most in- 
jurious kinds of dust are such as consist of hard, 
sharp, and angular pieces. 

Dr. Ogle, of England, has compiled a table* show- 
ing the mortality among British people (males) be- 



* Published as a supplement to the Forty-flfth Annual Report of the 
Kegistrar-General of England. For quotations and comments see 
"Practical Hygiene" by Dr. Louis C. Parkes, London. 



DUST IN THE AIR. 71 

tweeii the ages of twenty -five and sixty -five years, 
who are employed in certain widely different occupa- 
tions, including those of (1) coal miners, (2) carpen- 
ters, (8) bakers and confectioners, (4) plumbers, 
painters and glaziers; (5) masons and bricklayers ; 
(6) wool workers ; (7) cotton workers ; (8) quarry - 
men (stone and slate) ; (9) cutlers ; (10) file -makers ; 
(11) earthenware manufacturers; (12) Cornish tin 
miners. It is found that these trades stand in the 
order in which they are given '^ above in the scale of 
increasing mortality among their followers ; that is to 
say, among people employed in the occupations named, 
the English coal miner is freest from lung disorders, 
and the Cornish tin-miner is of all most subject to 
such troubles. Indeed the mortality from lung dis- 
eases alone among the miners of tin ore is 3.5 times 
that among the coal -diggers ; nearly 66 per cent, of 
the total mortality among tin -miners is due to 
bronchial disorders, and the death-rate among this 
class of workmen is nearly three times as high as that 
of the male population of their region considered as a 
whole. 

Dr. Ogle attributes the comparative safetyf of coal 
mines in this respect, namely, to the softness of coal- 
dust particles and to the freedom of such from all 
sharp angles and points. He believes also that coal- 



t The reader should guard himself against an exaggerated opinion 
of the safety of coal-miners. The immunity spoken of in the text has 
reference to lung diseases only, and the comparison is made with other 
dust-inhaling occupations only. The miner of coal is certainly far more 
liable to bronchial troubles than persons protected from all dust 
would be. That coal mining is a hazardous occupation from liability 
to terrible accidents needs no argument here. 



72 DOMESTIC SCIENCE. 

dust exercises an effect in hindering the progress of 
phthisical disorders. Such comparative immunity 
from lung diseases among the miners of coal, is still 
more surprising when we consider that these men are 
kept while at work in a heated atmosphere, vitiated 
from constant emanations of noxious gases from the 
walls, ceilings and floors of the black, subterranean 
passages.* The tin-miners on the other hand, though 
laboring under many conditions similar to those 
attending the coal workers, inhale dust consisting of 
hard, sharp and irritant particles. 

To further illustrate the effect of dust upon the res- 
piratory organs, let us consider briefly the effects of 
certain other branches of dusty toil. Dr. Hall tells us 
that the average life of fork grinders is about twenty - 
nine years, and that of edge-tool workers generally 
about thirty-one years, the cause of death in the major- 
ity of cases being lung troubles, induced through the 
inhaling of metallic particles and the dust arising from 
the wear of the grindstones. Pearl button makers 
suffer from such disorders to a marked extent, as do 
also workers of flax and cotton, and employes in 
paper factories. 

These examples illustrate the mechanical irritation 
on the air passages occasioned by dust, much of which, 
in a toxical sense, may be considered innocuous, there 
are other occupations, however, in the course of which 



* Let it be remembered that these statements regarding the health- 
tulness of coal-miners are applied to the workers in British mines only. 
The laws of England regarding the ventilation of mines, especially 
coal-mines are strict. The copious flow of air through the under- 
ground passages carries away noxious gases and dust as fast as 
liberated. 



DUST IN THE AIR. 73 

the Avorkmeu are exposed to poisonous dust. Such 
is the case with brass founders and copper-smiths, 
among whom mortality runs high from copper poison - 
ing ; "brass-founders' ague" used to be a popular 
name for disorders of this sort. Lead poisoning is a 
frequent cause of death among plumbers and painters, 
the former contracting the disease from the inhalation 
of volatilized lead and lead oxide, and the latter from 
breathing air laden with white -lead dust, and from 
absorbing through the skin the poisonous lead com- 
])Ounds of their paints. Mercurial poisoning causes a 
rise of mortality among all who work with the curious 
quick- silver, and arsenical fumes carry many to early 
graves from the ranks of ore roasters. 

The cascis already referred to are somewhat special 
in their nature, it is true ; comparatively few are called 
to labor and to suffer in such injurious occupations ; 
yet there are lessons in these examples which are ap- 
plicable to all people. We learn that dust of any de- 
scription is deleterious when introduced into the air 
passages of the body; care, therefore, should be exer- 
cised to escape the injuries thus indicated. 

The Creator has done much to arm His children 
against these inevitable dangers. Our nostrils are lined 
with stout hairs, vibrissae they are called, and these act 
somewhat as a sieve to the air that passes between 
them. The nose openings are the proper respiratory 
entrances to the lungs, and much of the dust, which, 
if breathing be carried on through the mouth, will 
surely find its way to the deeper air passages, will be 
arrested in its course if forced to thread the intricate 
passages of the nose. When a person is exposed to 



74 DOMESTIC SCIENCE. 

dust, the mouth should be kept closed. Street talk 
tends to evil in more ways than one ; dusty thorough- 
fares are not lit places for conversation. 

A further defence against the injuries of dust -laden 
air is offered by the peculiar structure of the lining 
membrane in the trachea and the lung passages. The 
inner surface of these channels is ciliated — that is, cov- 
ered with innumerable hair -like outgrowths (cilia), so 
fine as to appear under the low powers of the micro- 
scope like the pile on new velvet. These countless 
cilia are in a state of constant motion, like waving 
grain under the influence of a gentle breeze, and as 
the direct movement is always toward the mouth, there 
is a tendency to sweep upward from the lungs all solid 
particles that may have found lodgment upon the 
walls. When the dust thus carried reaches the throat, a 
cough suggests itself, an expectoration follows, and the 
intruding particles are ejected from the body. 

It will perhaps be interesting, and certainly instruc- 
tive, to inquire as to the nature of common street dust. 
Its grittiness declares the presence of earthy particles 
such as bits of pulverized stone ; this material is a 
natural consequence of the wear and tear of roads, and 
the more general disintegration of the rocks through 
natural agencies. 

But beside this purely inorganic or mineral matter, 
the microscope reveals many organic particles. Several 
investigators have turned attention to the composition 
of out- door dust, and from their observations we learn 
the following. Mingled with the structureless mineral 
particles are the siliceous shells of diatoms ; also spores 
of many of the lower plants ; fragments of straw and 



DUST IN THE AIR. 75 

hay, — these often partly digested, proving" that they 
must have traversed the alimentary tract of some 
herbivorous animal ; — grains of starch ; scales from the 
wings of butterflies and moths ; hairs of animals, and 
soft down from birds ; and bits of cotton, wool and 
silk. 

In addition to this varied assortment of inanimate 
matter, the microscope reveals the presence of many 
living organisms, whose minuteness is almost beyond 
description. Many of these are comparatively innocuous, 
though some have the power of producing specific 
diseases, provided they are taken into the system, and 
find there the nutriment necessary to their being. 
Such germs thrive within the body chiefly upon the 
products of deteriorated tissue ; a healthy system has 
power to resist the attacks of many noxious germs by 
refusing to afford them requisite nourishment. The 
person who has ignored the divine "Word of Wisdom," 
which is God's law of health, and who has weakened 
his body through injurious excesses, has little power of 
defence against the invading hosts of contagious germs. 
Temperance in all indulgences, and rectitude in all the 
duties of life, will combine their unconquerable forces 
against the deadly foe. 

Much of the out- door dust finds its way into the 
house, and there augments the ills resulting from the 
presence of household dust proper. The oft -quoted 
illustration is conclusive proof that dust pervades our 
homes — notice the path of a sun beam within a partially 
darkened room ; along the line of light innumerable 
"gay motes" appear, rising, sinking, with ceaseless 
motion, all made plain to our gaze by that efficient 



7G DOMESTIC SCIENCE. 

analyst, the solar beam. Professor Tyndal has em- 
ployed the electric arc instead of sun light in 
numerous investigations, and has clearly shown that 
the air in all places near the earth's surface is heavily 
dust- laden. The dust of rooms comprise all the in- 
gredients of street dust, and in addition many other 
particles arising from household wear and tear and the 
varied domestic operations. Common among these are 
fibres of many kinds from the carpets and draperies of 
rooms ; crystals of salt ; finely divided carbon as soot, 
lampblack, and coal-dust; bits of hair and wool; and 
epithelial scales from the skin and lungs of the in- 
mates. Of these, the last named, including all organic 
particles* arising from the bodies of living beings, are 
most to be feared. 

Such organic dust, if arising from the bodies of 
persons suffering from infectious diseases, may become 
the medium of deadly contagion. It is, of course, 
impossible to prevent the entrance and formation of 
dust within our homes ; the necessary wear of domestic 
operations will constantly give rise to detached part- 
icles ; we can scarcely hope to find a dustless house. 
Our efforts would be most wisely directed if applied 
toward the prevention of undue accumulations of the 
dust, and to averting, as best we can, the ill effects of 
its putrefactive changes. 

Many rooms are, from their construction, veritable 
dust-traps. Uneven wall surfaces, projecting door and 
window frames, cornices, ceiling and wall mouldings, 

*Dr. Lewis Parkes says of household dust : "It is thus seen to con- 
sist largely of organic refuse, often more or less putrescent, and its 
presence in the air assists in the production of the low state of health 
so common to the occupants of dirty, overcrowded houses." 



DUST IN THE AIR. 77 

all prove effective in entrapping dust particles and 
holding the same secure from the broom and duster of 
the most energetic house -maid. The floors are no less 
instrumental in this respect ; crevices between the 
boards hold immense quantities of dust ; heavy and 
immovable furniture renders a thorough and frequent 
cleansing scarcely possible ; but beyond all these, carpets 
stand forth as the chief of dust- catchers. The custom 
of covering every floor with woven carpets, which are 
removed only at intervals of months, is a deplorable 
one. Investigation by several English physicians have 
done much to prove this fact, and there are to-day 
many eminent medical practitioners who decline to 
undertake cases of illness if the patients are kept in 
carpeted rooms. Close polished or oiled floors are 
easily cleaned, if carpets are used at all they should be 
but lightly fastened. Indian matting has been re- 
commended ; this material is but slightly absorbent, 
and admits of ready cleansing. Oil cloth and linoleum 
may be used in dry situations ; if the floors areex2)osed 
to dampness, however, the use of such will favor the 
development of "rot" in the wood. 

Curtains of thick fabrics ; heavy draperies, wall 
hangings, lambrequins, and the like, all serve to gather 
and conceal dust. If such decorations are used at all 
they should be of light material, and be so arranged as 
to admit of ready removal and frequent cleansing. 

Rough or "flock" wall papers hold large quantities 
of dust, and some such papers give off particles of 
pigment from their own surfaces. This condition is 
especially undesirable if the loosely applied coloring- 
matters of the paper are of a poisonous nature. 



78 DOMESTIC SCIENCE. 

Much, has been written and said regarding the presence 
of arsenic in wall papers, and the deadly effects of the 
poison upon tlie inmates of rooms ornamented with 
such papers. Doubtlessly, the use of arsenical wall 
paper is a source of serious danger, and has produced 
even fatal results, but papers of this sort are far less 
common than has been generally supposed.* The 
writer has collected from the supply stores of Salt Lake 
City, and has analyzed 127 specimens of wall papers, 
of as many colors and kinds as could be found ; and in 
only four of them was arsenic present at all. The worst 
of these was a bright green with gilt markings, this 
contained per square foot between 7 and 8 grains of 
metallic arsenic, corresponding to nearly 10 grains of 
white arsenic. The use of such a paper on the walls 
of dwelling rooms would be a source of great 
danger. 

Tarkes reports the presence of arsenic in wall paj^ers 
in quantities varying from less than a grain to even GO 
grains per square foot. The same authority has 
classified the principal symptoms of arsenical poisoning 
from such cause, among which the following are 
prominent: — cough associated with nausea, diarrlKea, 
colic pains and cramps, dryness of mouth and throat 

*Arsenic and various other poisonous matters are used in eolorinjr 
many kinds of paper beside that designed for wall decoration. Even 
the tinted tissue paper used for the instruction and entertainment of 
children In kindergartens, are contaminated with poisonous colors, 
and cases of serious injury have resulted from the children's Iiabit of 
chewing such papers. It may be argued that paper should not be 
chewed; this is true, but numy children are apt to try their teeth on 
everything that they can get into their mouths. If paper contains 
l)oisonous pigments, as Dr. Youmans has said with a kind of grim 
iiumor, "such deadly additions utterly spoil the paper for dietetical 
purposes either for children or adults." 



DUST IN THE AIR. 79 

with intense thirst, severe lachrymation , and distressing- 
headache, and a marked debility of the whole system, 
which, ill extreme cases, leads to actual paralysis of 
the limbs sometimes followed by convulsions and death. 

Green papers are the ones most likely to contain 
arsenic, though the poison has been found in reds, 
browns and greys. The arsenical compound most 
used as a pigment is the arsenite of copper, commer- 
cially known as " Scheele's green," and composed of 
arsenic and copper in a combined form ; a still more 
attractive tint is produced by the aceto - arsenite of cop- 
per, commonly known as " Schweinfurth green." 
Prof. Johnson, of Yale, considers the last named as 
the most beautiful of all green pigments. Some ar- 
senical papers have the coloring matters so loosely 
applied that the poisonous particles become detached 
from the paper and permeate the room as fine dust, 
thus finding their way into the lungs of the inmates 
through the process of resjnration. In other cases, 
especially if exposed to dampness, the arsenical com- 
pounds rapidly undergo chemical changes whereby 
certain gaseous substances are generated, the chief of 
which is arseniuretted hydrogen — one of the deadliest 
of poisons.* 

A competent chemist could determine by very sim- 
ple tests whether arsenic was or was not present in any 
samples of paper submitted to him ; if the means of 
securing such a test be not at hand when selections of 

* Prof. Johnson says that Schweinf urth green when moist gives rise 
to the formation of the deadly arseniuretted hydrogen in great quan- 
tity. He has given a detailed account of the poisoning of a whole 
family from sleeping in a house, the walls of which were hung with 
paper of this dangerous though beautiful tint. 



80 DOMESTIC SCIENCE. 

wall paper are to be made, it would be safest to choose 
smooth papers, of light tints, with colors that cannot 
be easily rubbed off. Varnished papers are still bet- 
ter ; their colors are protected beneath a tolerably im- 
pervious coat, and they admit of washing. 



VENTILATION. 81 



CHAPTER 8. 

VENTILATION. 

HAVING conviuced ourselves that the atmosphere 
of dwellings is constantly becoming contaminated 
through additions of foul and poisonous matters ^ it is 
now a matter of importance and interest to consider 
the principal conditions attending the necessary purifi- 
cation of the air of our homes. 

Two general modes of accomplishing this have been 
attempted. The first consists in removing the vitiated 
air, and admitting in its place a supply of fresh air from 
without. This is commonly spoken of as ventilation 
proper. In the second method, chemical means are 
employed either to decomjDOse 04: to absorb the effete 
matters as fast as they are formed, thus maintaining in 
the enclosed atmosphere a normal state of purity. 
This is known as the chemical method. Of each of 
these general processes there are numerous variations 
as to details, but the chemical method has had but 
limited application ; we shall therefore consider here 
only the more important methods pertaining to ventil- 
ation proper. 

In devising plans for the ventilation of buildings, we 
are required to provide for the removal of foul air as 
fast as formed, and for its replacement by pure air 
from without. Attention must also be paid to the 
temperature of the entering air, for experiment and 
observation have shown that the introduction of large 
volumes of cold air into inhabited rooms may prove 



82 DOMESTIC SCIENCE. 

a source of serious injury. Draughts are also to be 
avoided, else ill effects will be manifest in the health of 
the inmates. 

The frequent changing of the air of an apartment 
involves the moving of immense masses of air, and 
some adequate power is requisite to the accomplish- 
ment of this. The means generally employed are 
dependent upon the heating of the contained atmos- 
phere or upon mechanical devices. It will be well to 
consider a few methods from each of these divisions. 

AIDS TO VENTILATION, DEPENDING UPON 
TEMPERATITKE CHANGES. 

It has long been held as an adage that "Heat causes 
expansion, and cold causes contraction." It is ap- 
j)licable to gases as well as to solids and liquids. When 
a mass of air is warmed, its particles are driven farther 
apart, thus requiring greater space ; the warmed air is 
specifically lighter than the cold, and consequently 
tends to rise ; this movement would produce an empty 
space or partial vacuum below, but the neighboring 
cold air promptly rushes in to fill such space. All 
natural movements of air, which we call winds, depend 
directly or indirectly upon this cause. Any means of 
warming and expanding the air in one place will cause 
there a rising current, and the space below will soon 
be filled with air of a lower temperature, which in turn 
will l)ecome heated, will rise and will make room for 
other air. This principle may be well observed in the 
entering and out -going currents of a room. If the 
temperature of the enclosed air be higher than that 
without, when the door is opened the cold air will 



VENTILATION. 



83 



enter in a current near the floor, while the warmed 
and lighter atmosphere will pass out by a counter 
current at the top. To make clear the course of these 
currents, place the door ajar, (see figure 32) and hold 
a lighted candle in the opening, first near the top, and 
then below. The flame will be driven outward at the 
top, and toward the room at the bottom. 

On warm days 
of summer, or by 
artificially cool- 
ing the enclosed 
air, these con- 
ditions of relat- 
ive temperature 
within and with - 
out may be re- 
versed ; then the 
outer air, being- 
warmer than the 
inclosed, would 
enter near the top 
of the door open- 
ing, while an out- 
w" going current 

Fig. 32. would be estab- 

Currents into and from a warmed apartment, ligljorl below 

In the experiments just described, the width of the 
door opening permits the passage of currents in oppo- 
site directions ; with more contracted spaces, however, 
such counter currents would seriously interfere with 
and perhaps totally neutralize each other. To illust- 
rate this, provide a small flame, as that of a burning 




84 



DOMESTIC SCIENCE. 



candle ; surround such with a good sized lamp chimney, 
set in a shallow dish containing a little water so as to 
seal the bottom. The flame soon dies out, smothered 
by the nonsupporting products of the combustion. Now 
divide the chimney passage by inserting a strip of metal, 
thin wood, or even of stiff paper, as shown in figure 33, 
the candle may now be kept burning. A bit of smoulder- 
ing paper held at the top will show the existence of up - 
ward and downward currents. 

This clearly demonstrates 
the necessity of providing 
separate openings as inlet and 
outlet for the air of any room. 

Upon this simple principle 
the best systems of mine ven- 
tilation are founded. In the 
case of a deep mine, it is usual ^^^^ 
either to sink two shafts or to Fig. 33. 

construct a bratticed single Opposite currents in a divided 

channel, 
shaft. The underground 

passages are so connected as to form a series of uninter- 
rupted channels from one shaft to the other, see figure 34 . 
As long as the air remains at the same temperature in 
both, no movement will take place ; but by placing a 
fire at the bottom of one shaft, the air column above be- 
comes expanded, and rises ; this upward movement is 
balanced by a corresponding downward current through 
the other shaft. By such means an effective ventilating 
action is maintained. 

A principle exactly opposite to that of creating up- 
ward currents by means of heat has also been practic- 
ally applied. This consists in causing a descending 




VENTILATION. 



85 



current by cooling the air above. Upon this principle 
Lyman's ventilator (figure 35) is constructed. This 

1/ 




Fig. 34. 
Upcast and downcast currents in a mine. 

device consists of a box containing ice (a) the bottom 
(/>) is perforated, and a gutter and waste pipe (c) are 
arranged below, to catch the water from the meltiiig 
ice, a large flue (d) conducts the cold descending air 
into the rooms ; an upper box (e) usually made of wire 
contains charcoal, which serves to purify the entering 
air and also to retard the melting of the ice.* 

Even within closed rooms, moving currents with 
consequent draughts are frequent. During cold weather, 
the windows are considerably colder -than the thicker 



* Youman's says of this ventilator, "Tliis arrangement on a small 
scale has been mounted on secretaries, to secure a cool and refreshing 
iiir while writing; over heds to cool the air while sleeping; and over 
cradles to furnish pure air for sick children." 



86 



DOMESTIC SCIENCE. 



walls, consequently the inside air in contact with the 
cold glass becomes chilled and falls ; while a warmed 
current from other parts of the room sets in to fill the 
space vacated by the descending cold air. A person 
sitting by a window under such circumstances would 
be entirely enveloped in the falling cloud of cold air, 
with great detriment to his health. To lessen this 
danger, builders now plan double windows consisting 

of an outer and an inner 
sash, with a few inches 
space between. The air 
within this space serves as 
a non-conducting wall 
separating the outer cold 
atmosphere from the 
warmer air of the room. 
By holding a candle flame 
near windows, and along- 
side the walls, the presence 
of complicated currents 
within the room will be 
at once revealed. Most 
of the simplest methods 
of ventilation are associat- 
ed with the means of 
warming the apartments ; 
indeed the subjects of 
ventilation and warming- 
are so closely related, that to consider them independ- 
ently of each other would be almost impossible. 

A good fire in an open grate necessitates an ample 
chimney draught ; the rising current within the flue cx- 




Fig. 35. 
Lyman's ventilator. 



VENTILATION. 8 7 

ferts a powerful aspirating effect, which results in the 
ready removal of air from the room. A correspond- 
ing quantity of other air must ent^r, to replace that 
which has been taken away. This incoming air causes 
a powerful current through the room toward the 
grate ; indeed, in the case of the wide open grates of 
olden times, the draught was so great that our worthy 
ancestors found it necessary to provide specially con- 
structed seats, called settles, with high close backs, for 
use before their roaring fires. 

In comparison with these high fire places^ capable 
of admitting the Yule logs without difficulty, the open 
grates of modern times seem very much contracted ; 
the space above the fire bars, — and this largely determ- 
ines the aspirating power of the grate, — being now re- 
duced to the smallest possible dimensions. Many 
forms of "ventilator -stoves" have of late appeared for 
sale. Such a stove is constructed with a double casing ; 
air enters below, and after becoming warmed it escapes 
into the room through a perforated top. 

The aspirating effects of a chimney increases in pro- 
Xjortion to the energy of the fire ; though observation 
has proved that a decided draught is noticeable in chim- 
neys even when no fire is in the grates. If a chimney 
be constructed with a double flue, one division may be 
used specially as a ventilating shaft ; the air within it, 
being warmed through proximity to the heating flue, 
will rise with vigor. An objection to the use of double 
flues has been found in the fact that, if of improper 
construction, or if there be no adequate inlet for air to 
the apartment, they are apt to permit downward currents , 
and thus to draw into the room smoke from the fire flue. 



88 



DOMESTIC SCIENCE. 



The apertures that lead from the room into the flue 
^re usually guarded by adjustable registers, the com- 
monest form of which consists of an iron grating and a 
movable back, so arranged that the passage may be 
opened or closed at pleasure. The efficiency of such a 
register may be greatly increased by attaching to the 
inside of the bars a flap of thin oil cloth or of oiled 
silk ; this will yield to pressure from the room toward 
the chimney, but the least impulse in an opposite di- 
rection will cause 
i^i£ ^i>ry^^^y/.^^^7^ \ %,::^2^^^ the curtaiu to be 

pushed in close 
contact with the 
inside of the regis - 
ter, thus prevent- 
ing the entrance of 
back currents into 
the room. Perhaps 
the best contriv- 
ance of the kind 
is the Arnott valve, 
which consists of 
a movable door of 
metal, set in the 
chimney aperture, 
and so delicately 
adjusted as to yield 
to the slightest cur- 
rent toward the 
chimney, and to 

close firmly and easily when pressed in an opposite 

direction. 

For the ventilation of large buildings many devices 




Fig. 36. 
Gillis system of ventilating. 



VENTILATION. 89 

depending upon the expansion of air by warming have 
been proposed. A very efficient method is known as 
the Gillis system ; this however can be used only in 
steam warmed buildings. As is shown in figure 36, a 
large [shaft extends from the lowest floor through the 
roof. Up the center of this shaft a steam pipe is car- 
ried. In each room, two openings, one at the top and 
the other near the floor, communicate with the shaft ; 
these apertures are provided with registers and auto - 
matic valves. The heat of the steam pipe causes a 
powerful upward current, by which air is drawn from 
the rooms. 

MECHANICAL AIDS TO VENTILATION. 

Many forms of air -propellers have been proposed for 
purposes of ventilation. Most of them possess some merit, 
and some of them rank among the most efficient of ventil - 
ators. The exhaust fan seems to be a favorite device. 
Dr. Mott speaking of the Blackburn fan, one of the most 
efficient kinds, states that a single 48 inch fan, if 
made to run at the rate of 500 to 600 revolutions per 
minute, will carry off 30,000 cubic feet of air per minute. 

Revolving cowls on chimney tops, if properly con- 
structed, serve to increase the aspirating effects of 
chimney flues. 

Thus far our attention has been applied to methods 
for removing the air from rooms ; adequate means for 
introducing a supply of fresh air are also to be con- 
sidered. Many common forms of inlets are objection- 
able because of the injurious draughts to which they 

give rise. 

In the ventilation of large buildings, pipes are often 

employed for conveying air to the interior ; these can 



90 



DOMESTIC SClfeNCtei 



be easily operated with good results ; but in small 
dwellings, windows and transoms are usually relied 
upon for admitting air. Where inlet pipes are used, 
however, a great advantage is possessed in the ease with 
which the incoming air may be warmed. The pipes 
may be passed through a heating box connected with 
the furnace ; and if the air thus warmed be found 
deficient in moisture, evaporating pans of water may 
be placed in the course of the stream. 

By opening the upper sash of a window, a strong 
entering current may be established. The cold air 
however, will fall rapidly, without diffusing itself suf- 
ficiently throughout the room. If there be a fire in the 

room, this current of 
cold air w ill continue its 
course to the grate, and 
thus be speedily taken 
from the room, having 
served but little the pur- 
poses of ventilation. 

It has been proved to 
be advantageous to 
place a board at an ang- 
le on tri3 upper part of 
the sash, so as to de- 
flect the entering cur- 
rent toward the ceiling; 
(see figure 3 7.) 

On the same principle, 
the efficiency of tran- 
soms may be greatly 
increased by hinging them at the bottom, so that 







Fig. 37. 
Entering current of air deflected to- 
ward ceiling. 



VENTILATION. 



91 



they may be set obliquely 




Fig. as. 
Transom hinged so as to deflect 
„ currents toward r eiling. 




Fig. 39. 

(Jurrents entering between window 

sashes. 



towards the ceiling, as 
in figure 38. 

With ordinary win- 
dows it is a good plan, 
and one that is widely 
practiced, to raise the 
lower sash, and place 
beneath it a strip of 
board, from four to six 
inches wide and of length 
sufficient to extend across 
the window^ opening, 
see figure 3 9 . This leaves 
a space between the 
sashes, through which 
air will enter the room, 
the current being direct- 
ed upward. Before fall- 
ing, the fresh air will 
have been diffused. 

For breaking up the 
entering current so as to 
aid in its diffusion, 
sheets of finely perfor- 
ated metal may be in- 
serted in the upper sash 
in place of the ordinary 
glass panes, or gratings 
with inclined slots may 
be used to advantage. 

It is possible to utilize 
windows both as inlet 
and outlet air passages. 



92 DOMESTIC SCIENCE. 



CHAPTER 9. 

SOME PROPERTIES OF HEAT. 

''PHE close relation existing between the processes of 
1- ventilation and those of house warming has been 
already mentioned. Incidental reference has been 
made to some methods of domestic warming, but be- 
fore attempting any detailed consideration of the sub- 
ject, it will be well to turn attention to some of the 
simple principles by which the form of energy known 
as heat is controlled. 

Heat is that force which, when operating upon the 
nerves of the living body, produces the sensations of 
warmth and cold. The true nature of heat, as indeed 
of all other forms of force, is very imperfectly under- 
stood by mankind ; but it is a general belief among 
experimenters and thinking men, that heat in a body 
is a manifestation of motion among the particles. The 
plausibility of this view is strengthened by the fact 
that motion may be transformed with heat; and con- 
versely, heat may be made to originate motion, with 
but little unaccounted loss of energy in either case. 
There is good reason for believing that as a body 
grows warm its particles are made to move within 
certain limits, with increasing speed, and at the same 
time they are driven farther apart, and thus the size of 
the bodv is increased. In the case of a fusible solid, 
iron for example, the temperature may be raised till 
^he particles are so far separated that their cohesion is 




SOME PROPERTIES OF HEAT. 93 

greatly diminished, and the liquid state results. If 
the molten material be still more highly heated, the 
gaseous condition may be reached, vapor of iron 
corresponding in physical state to steam being pro- 
duced. 

The general effect of heat when applied to bodies is 
to cause expansion. This is true of solids, liquids, and 
gases. Figure 40 illustrates a common experiment 

upon this point. 
A ring and a ball 
of metal are pro- 
Fig. 40. vided ; they are of 

Ball enlarged by heat. g^^j^ relative sizes 

that the ball while cold will readily pass through the 
ring. By heating the ball, however, it becomes en- 
larged, and is not able to pass through the ring. 

The blacksmith applies a practical knowledge of 
this principle when he heats the tires of wheels before 
fitting them about the felloes ; the iron, he knows, 
will contract in cooling and thus the tires will fit the 
more tightly. 

The force exerted by the expansion of solids through 
increasing temperature, is enormous. The iron rods 
and cables of which suspension bridges are made, move 
through considerable distances in the course of a 
season's range of temperature.* 

A difference of 81° F. between summer and winter is 
by no means uncommon ; yet such a change of 

* Of the huge Brittania bridge an observer has said, "The ponderous 
iron tubes writhe and twist lilce huge serpents under the varying in- 
fluences of the solar heat. The span of the tube is depressed only a 
quarter of an inch by the heaviest train of cars, while the sun lifts 
it two and a half inches." 



94 DOMESTIC SCIENCE. 

temperature operating on a bar of wrought iron 10 
inches long, would increase its length about 1-200 inch ; 
this force is equivalent to a strain of 50 tons. It has 
been shown by careful trial, a bar of iron measuring 
1 square inch in cross -section, in being warmed from 
the freezing point to dull red heat, will elongate about 
()-1000 of its original length. The mechanical strain 
needed to stretch such a bar this amount is about 90 
tons. 

Many practical illustrations of this principle may be 
observed in household operations. The pendulum 
rod of a clock is sure to elongate during warm weather 
and to shorten during the cold season. Xow the 
office of the clock pendulum is that of a regulator to 
the time piece ; by its swinging it controls the speed 
of the machinery. Observation proves that a long 
pendulum requires greater time to vibrate than does a 
short one. In warm weather, therefore, the pendulum 
is apt to swing more slowly and thus cause the clock 
to fall behind in its indications. In cold weather, on 
the other hand, the fast -moving pendulum causes the 
clock to run ahead of the true time. These irregularities 
may be in some degree corrected by raising or lower- 
ing the pendulum "bob" in accordance with the pre- 
vailing conditions of temperature. Some pendulums 
are so constructed as to partially regulate themselves. 
These are known as compensation pendulums, the 
simplest form of which is the gridiron penduhim, 
sketched in figure 41. The pendulum rod consists of 
bars of two different metals, usually steel and brass, 
so arranged that the bars of one material can elongate 
only in a downward direction, they being fixed above ; 



SOME PROPERTIES OP HEAT. 



95 



While the other bars can expand only in an opposite 
direction. Thus the upward and downward expansion 
may be made to compensate each other, and the pen- 
dulum be kept of the 
same actual length. 

Another form of 
compensation pendu- 
lum is the mercurial 
bob, shown in figure 
42. In this the lower 
part of the pendulum 
consists of a frame- 
work or box, within 
which a number of 
glass vessels, contain- 
ing mercury may be 
set. Two such ves- 
sels are shown in the 
figure. As the pen- 
dulum rod elongates 
through increasing 
temperature, the 
mercury in the open 
vessels, also expands 
and consequently 




Fig. 41. 
Gridiron compensa- 
tion pendulum. 



Fig. 42. 

rises. These opposite Mercurai pendu- 
lum bob. 
expansions may neu- 



tralize each other's effect, and the "center of oscilla- 
tion," which determines the true length of the pendu- 
lum, may remain unchanged. 

Although we observe fewer illustrations of the ex- 
pansion of liquids and gases under the influence of 



96 



DOMESTIC SCIENCE. 




Fig. 43. 

Liquid expanding by 

lieat. 



heat, yet careful experiment will show that these 
bodies, too, obey the general law. Take a glass 
bulb attached to a stem or a small glass flask as 
as in figure 43, provided with a tight-fitting cork 

through which passes an open 
tube ; fill the vessel with water 
and gently warm. The liquid 
rises in the tube under the ex- 
pansive influence of the heat. 

Now take a similar bulb or 
flask, empty and dry ; invert and 
place the stem in a vessel of water 
(see figure 44). Grasp the 
bulb in the hand ; the warmth 
will cause the air within to ex- 
pand till it drives the water from the hollow stem and 
escapes in bubbles through the liquid in the tumbler. 
Now remove the hand ; as the air cools it tends to 

resume its former dimen- 
sions ; but as a portion has 
escaped, a corresponding 
quantity of water enters the 
bulb. 

Upon the expansion of 
liquids by heat depends the 
action of the ordinary Ther- 
mometer. The word is de- 
rived fron the Greek thermos — heat, and metron, 
measure, therefore a measurer of temperature. As 
commonly constructed, it consists of a bulb of thin 
glass with which a long hollow stem of fine caliber is 
continuous ; this is shown in figure 45. A quantity of 




Fig. 44. 
(lases expanding wlien warm 



SOME PROPERTIES OF HEAT. 



97 



mercury (quicksilver) or of alcohol fills the bulb and 
extends some distance into the tube. 
The stem is hermetically sealed at the 
top, and the space above the fluid is a 
vacuum, the air having been removed 
therefrom before the tube was sealed. 
A rise of temperature causes the liquid 
within the bulb to expand ; the only 
direction in which it is free to move is 
the upward one ; the liquid therefore 
rises. A cooling effect will result in a 
contraction of the fluid, and a conse- 
^^ quent fall of its level within the tube. 

Fig. 45. 

Thermometer-bulb Such an instrument will reveal the 
and stem. p^^^j^ ^j ^ difference of temperature ; 
but the degree of difference cannot be determined till 
the thermometer is graduated. The inventor of the 
instrument was a German scientist, one Gabriel 
Fahrenheit, who lived in the early part of the last 
century. He set his thermometer in ice, and marked 
upon the tube the level at which the mercury stood : 
this degree of temperature he properly called the 
''freezing point." The instrument was then trans- 
ferred to a bath of boiling water, and the level at 
which the mercury then stood was marked on the tube, 
and the temperature was named "boiling point." 
In a somewhat arbitrary manner, Fahrenheit then 
divided the space between the marks on the tube into 
180 sections; these he called "degrees." Fahrenheit 
knew that ice was not the coldest thing in existence ; 
by mixing snow or cracked ice and salt he produced a 
much lower temperature ; so in a mixture of this kind 



98 DOMESTIC SCIENCE. 

he immersed the thermometer, and the level of the 
merciuy was marked and called "zero." The space 
between that point and the freezing point was divided 
into 32°. On the Fahrenheit scale, therefore, the 
freezing point is 32° above 0°, and the boiling point 
is (180° + 32° =) 212° above 0°. AYith a tube of 
uniforrii caliber, the graduations may be carried above 
and below these points. This scale of thermometric 
readings, though very arbitrary in its nature, is the one 
most generally used among English speaking nations ; 
though for scientific and technical purposes another 
system has been adopted. 

A Swedish scientist named Celsius, proposed to call 
the freezing point 0°, and the boiling point 100°, the 
space OM the thermometer stem between the points 
thus indicated being divided into 100 equal parts ; 
and the graduation being continued both above and 
below these fixed points. The Celsius graduation is 
sometimes called the centigrade scale. The heat 
needed to raise a quantity of water from the freezing 
Ijoint to the boiling temperature will cause the mercury 
in a thermometer graduated after the Fahrenheit system 
to rise from 32° to 212° or through a space of 180 
degrees ; and the same heat would raise the mercury 
in a Celsius thermometer from 0° to 100°, or through 
a space of 100 degrees. It will be seen then that: 

1S0° F. correspond to 100° C. 

Then '.)° F. •• >••' 5° C. 

5' 
1° F. corresponds " ^g^C. 

, And 1° C. •' •• :' F. 

o 



SOME PROPERTIES OF HEAT. 



99 



Now, although as shown above, 180 of the Fahren- 
heit degrees correspond to 100 of the Celsius degrees, 
it does not follow that the 180th degree above 0° F. 
should correspond to the 100th degree adove 0° C, 
because the of the Celsius scale marks the freezing 
point, while the of the Fahrenheit scale is 32 
Fahrenheit degrees below the freezing point. An 
allowance for this must be made in transforming the 
readings of one scale into terms of the other. The 
truth of the following formulae will be seen without 
difficulty by the thoughtful student : 



F. 
C. 



32. 



mi 



C. -f 

(F.— .H2). 

Figure 46 shows a thermometer 
of simple construction, with scales 
attached after both the Fahrenheit 
and the Celsius (or centigrade) 
systems. 

The thermometer is an instru- 
ment of great utility, and it certain - 
ly deserves a more extended service 
than is commonly allowed it in 
domestic operations. We are apt 
to place too much reliance in the 
indications of our organs of sense 
as to temperature, and t>ese indi- 
cations are often deceptive. 



Fig 4G. *Tlie old-time demonstration will i 

^*^^™th?F^andthe'^^^ the point. Provide three bowls orb, 
C. systems. medium size; into the middle one pu . 

of medium temperature, say about G 
into one of the remaining vessels put some ice water ; with the 
ace water as hot as can be borne without injury when in con 



rate 
^f 



100 DOMESTIC SCIENCE. 

Many cheap thermometers are inaccurately gradu- 
ated ; their error, however, seldom exceeds 2°. For 
domestic purposes a thermomemter possessing the fol- 
lowing characteristics will be found most generally use- 
ful : 

(1) The graduation markings should be on the glass 
stem rather than upon an attached scale. 

(2) If set in a frame the tube should be readily re- 
movable that it may be used when so needed, to de- 
termine the temperature of liquids. 

(3) The graduations should extend at least from 
0° to 212° F. 



with the flesh. Now immerse one hand in the hot liquid, the other in 
the ice water ; take notice of the sensations, then plunge both hands 
into the bowl of water at ordinary temperature. To the hand that 
came from the hot water this seems unendurably cold; to the hand 
just taken from the ice water, the contents of the middle bowl seem 
to be intensely hot. Neither of these sensations indicates the truth. 



COMMUNICATION OF HEAT. 101 



CHAPTER 10. 

COMMUNICATION OF HEAT LATENT AND SPECIFIC HEAT. 

IF A BAR of Iron be set with one end in a fire, after 
a very short time the other end will have become 
hot. It is plain that in this case the heat must have 
come from the fire : it must have been communicated 
along the line of particles from one end of the bar to 
the other. To be more accurate in expression, we 
should say the heat has been conducted along the iron : 
in consequence of the property here shown the metal 
is said to be a conductor of heat, and this process of 
heat -communication is known as conduction. 

An impressive illustration of this effect may be pro- 
duced as follows :— Provide a thick iron or copper 
-. about a foot long (see figure 47), by means of wax 
the bar at equal distances a number of mar- 
bles V, ' Mllets. Insert one end of the bar in a 




Fig. 47. 
LHeat being conducted along a bar of iron. 

flame : one by one the balls are melted off, showing by 
their successive falls the invasion of the particles by 
the heat. 




102 DOMESTIC SCIENCE. 

An apparatus designed to demonstrate the relative 
conductivity of different metals is shown in figure 48, 

it consists of a brass box, carry- 
ing a number of rods of differ- 
ent substances. The free ends 
of the rods are first covered 
with wax : the box is then 
tilled with hot water, and the 

Fig. 48. order in which the wax on each 

Condiictometer. t ,. .^ . , -, 

rod liquifies is noted. 

The common metals and alloys are arranged in the 
following order with respect to their conducting pow- 
ers : (1) silver; (2) copper; (3) gold; (4) brass; 
(5) tin ; (6) iron ; (7) lead ; (8) platinum ; (9) Ger- 
man silver: (10) bismuth. 

To these may be added several common substances 
other than metals, arranged on the same plan : (11) 
marble; (12) porcelain; (13) clay; (14) woods; 
(15) fats; (16) snow; (l7) air; (18) silk; (19^ 
charcoal; (20) cotton; (21) lampblack; (22'^^ 

Most liquids are poor conductors «^^ 
statement may seem strange when ue iact 

that heat seems to be uni^^r ' ■ .^i throughout 

liquid masses. Su'^^ . ^i. heat is effected by 

other means thr.. ..ction as above described. 

When licr ■ ^re heated they become specific - 

"''v jnsequently they rise, thus making 



■■'- ar most efficient fabrics for clothing are poor conductors of lieat. 
A coat of fur or of woven wool, if wrapped about a living being will retain 
the bodily lieat: if wrapped around a block of ice the same garment 
keei)S the ice cold. In the one case the wrapping prevents tlie escai)e 
of lieat from the waruier body to the cooler air: In the other It guards 
the ice against access of warm air. 



COMMUNICATION OF HEAT. 



103 




Fig. 49. 

Convection of heat in a body 

of liquid. 



room for colder particles, which in turn become 
warmed and rise. The course of these rising currents 

of warm water and descend- 
ing streams of cold may be 
followed in the warming of 
a flask or beaker containing 
water, to which a small quan- 
tity of sawdust or other finely 
divided, opaque matter has 
been added, (see figure 4 9). 
Such a mode of diffusing 
heat by the successive warm- 
ing of separate particles, is 
known as convection. If 
Avater were a good conductor of heat it would trans- 
mit heat as well in a doAvnward as in an upward direc- 
tion. The inability of the liquid 
to do this may be thus shown : A 
funnel (figure 50) with a wide 
throat is fitted with an " air ther- 
mometer " passing through its 
neck and dipping in a vessel of 
water below. Water is poured 
into the funnel till the thermome- 
ter bulb is covered ; a little ether 
is then poured upon the water and 
ignited. Though the flame be 
within half an inch of the bulb, the 
Fig. 50. heat is conducted downward so 

^^^ condJc^ heat"1n ^a ^^^wly as scarcely to cause an ex- 
downward direction, pansion within the bulb. 

There is a third method bv which heat is diffused, as 




104 DOMESTIC SCIEMCE. 

may be shown by holding the hand in front of a fire. 
The flesh soon becomes warmed ; not by conduction, 
for between the hand and the fire there is no material 
connection, except the air, and air like all gases, 
is of but slight conductivity ; neither is the hand 
warmed by convection, for warm convection currents 
are ascending ones. It is plain that the heat must have 
penetrated the intervening air ; must have traveled 
from the fire to the flesh. Such mode of heat com- 
munication is known as radiation, and the heat so 
transmitted is called radiant heat. Radiant heat passes 
outward from its source, along straight lines in all 
directions ; the heat rays fall upon objects in their 
course and warm them, without, however, raising the 
temperature of the intervening air. Radiant heat may 
be transmitted in a vacuum, thus proving its inde- 
pendence of air as a medium of conveyance. The laws 
of its motion ai'e similar to those of light ; it comes to 
us from the sun associated with light, both traveling 
at the rate of 185,000 miles per second. The intensity 
of radiant heat diminishes as the square of the distance 
from its source increases ; therefore a person sitting 
within two feet of a fire would receive four times as 
much radiant heat as would fall upon a second person 
situated four feet from the fire. 

HIDDEN HEAT : LATENT AND SPECIFIC. 

In speaking of the measurement of heat, we have 
thus far dealt only with thermometric indications ; yet 
there are many operations in the course of which heat 
changes are not revealed bv the thermometer. Thus a 



COMMUNICATION OF HEAT. 105 

vessel containing ice at the freezing temperature may 
be exposed to heat, but until the ice has become thor- 
oughly liquified the thermometer would indicate no 
rise. The energy has not been lost however ; it has 
been expended in separating the ice particles, and in 
overcoming the cohesion between them so as to pro - 
duce the liquid state ; and this energy will be again 
freed as heat when the liquid returns to the solid 
condition.* The heat so escaping thermometric 
measurement is known as latent heat. The heat thus 
rendered latent in the melting of ice is about 80 times 
that required to warm the same amount of water 1° C. 
Heat is also rendered latent in changing substances 
from the liquid to the gaseous state. In the boiling of 
water much heat is absorbed, the steam being no 
warmer according to the thermometer than was the 
water at the instant of its transformation. Experi- 
ment shows that to vaporize a given quantity of water 
at the boiling temperature requires about 537 times 
as much heat as is needed to raise that same quan- 
tity of water through a range of 1° C. 

Under all circumstances, water appears compara- 
tively sluggish in responding to the in'fluences of heat. 
The amount of heat that would raise a pound of water 
1° in temperature, would warm 30 lbs. of quicksilver 
through the same range. We perceive then that dif- 

* Though paradoxical, it is true that the freezing process is associ- 
ated with the liberation of heat, and is therefore in one sense a warm- 
ing process. In passing from the liquid to the solid state, water gives 
out all of the heat acquired by it and rendered latent in melting. This 
principle is often made use of to prevent the freezing of vegetables and 
fruits during cold weather. Open vessels of water placed in proximity 
to such perishable articles in a closed room, will liberate sufficient heat 
to warm the air of the room through a range of several degrees. 

5 




lOfi DOMESTIC SCIENCE. 

ferent substances possess varying capacities for heat. 
If to warm a quantity of water through a given range 
of temperature requires 30 times as much heat as would 
serve to similarly warm an equal amount of mercury, 
then in cooling, the water would give out 30 times as 
much heat as would the mercury. The relative capa- 
city of substances for holding and retaining heat 
is known as specific heat. 

An instructive demonstration of specific heat may be 
made thus (figure 51) : Procure 
a number of small balls of equal 
weight, one each of iron, copper, 
silver, tin, lead, and bismuth. 
Heat all to the same tempera - 

ture by immersing them in a 

Fig. 51. bath of hot oil ; then place them 

^''"SiiS^^'liilS^^'way on a cake of paraffin or of bees 

through wax with vary- ,^„^^ T'v.r. ii^^n o/->^ii mr.ifc. ifo 
ing rapidity, because of ^^^x. Ihe iron soon melts its 

hS '"''''^''''^ '^'''^' way through the wax ; then fol- 
low in order the copper, the silver, the lead and 
the bismuth. Some of the metals therefore are much 
better absorbents of heat than are others. 

Considering water as the standard, the specific heat 
of several common substances may be expressed as 

follows : 

*Water - - - - - - 100 

Air ------ - 23.75 

* " It is hecause water is capable of receiving so much heat that it is 
better adapted than any other substance to quench thirst. A small 
quantity of it will go much farther in absorbing the feverish heat of 
the mouth and throat than an^(iual amount of any other liquid. When 
swallowed and taken into the stomach, or when poured over the in- 
flamed skin, it is the most grateful and cooling of all substances. For 
the same reason, a bottle of hot water will keep the feet warm much 
longer than a hot stone or block."'— Dr. YoijM.\xs. 



COMMUNICATION OF HEAT. 107 

Oxygen ------ 21.75 

Sulphur ------ 20.26 

Iron ------- 11.38 

Copper ------ 9.52 

Silver ------ 5.70 

Tin ------ - 5.62 

Mercury ------ 3.33 

Lead ------- 3.14 

Bismuth ------ 3.08 

Alcohol ----- - 5.05 

Ether _.---- 5.4(; 

The beneficial effects resulting from the operation 
of these laws of latent and specific heat are of the 
highest order. Suppose for a moment that the princi- 
ple of latent heat did not exist. As spring time ap- 
proached, the vast masses of ice and snow of lakes 
rivers and mountains would become warmed to the 
temperature of 32° F., the melting and freezing point 
of water ; and the least further rise would result in an 
immediate mighty bursting of the bonds of frost ; the 
ice and snow would become almost instantaneously 
liquified, and wide -spread destruction would be in- 
evitable. But the All -seeing One has wisely decreed 
that much heat shall be required to change the physical 
state of matter ; such changes must then of necessity be 
gradual ; and in orderly march, with the precision of 
prisoners under full control, these frost-bound parti- 
cles return to their condition of liquid liberty. So, too, 
the advances of winter are restrained and the severity 
of the season is tempered by reason of the great 
amount of latent heat escaping from freezing water. 
But for the operation of this principle, a fall of tem- 
perature only one degree below the freezing point, 
would result in the instantaneous formation of ice on 
a stupendous scale. Try to think of the possible re- 
sults, if as soon as the boiling point were reached, 



108 DOMESTIC SCIENCE. 

water was instantly converted into steam. Such a 
prodigious expansion would be followed by demonstra- 
tions of explosive violence, such as man cannot con- 
ceive of. And but for its high specific capacity for 
heat, water would respond with alarming readiness to 
the slightest changes of temperature ; and the result could 
not be other than destructive. But such dire calamities 
are prevented through the operation of the laws of 
nature, which are the laws of God. These stupendous 
forces are under perfect control ; the Mighty One holds 
them in His power. 



PRODUCTION OF HEAT. lOO 



CHAPTER 11. 

PRODUCTION OF HEAT ; FUELS AND FLAME. 

THE earth is warmed by the heat rays that come to 
it from the sun. That brilliant orb has been con- 
stituted by the Creator as the source of warmth and 
light and chemical energy for our globe. During the 
cold season, when we receive less directly these ener- 
gizing rays, and during the night, when the hemi- 
sphere on which we live is turned away from the 
glowing sun, and for special purposes at other times, 
it is necessary to provide for the production of arti- 
ficial heat. The common methods of accomplishing 
this depend upon the chemical energy of combustion, 
and when employed for such purposes combustible 
substances are known abs fuels. 

To aid us in comprehending the chemical processes 
attending the burning of fuel, let us examine a small 
flame ; that of a candle will answer our purpose well ; 
but first — a word as to the candle itself. A candle 
consists of a solid cylinder of wax or tallow, or some 
such easily fusible and combustible material ; this is 
the fuel. In the middle of this cylinder a wick is 
placed ; this serves by its porous nature to convey 
the melted wax from the little cup at the top of the cyl - 
inder to the region of the flame. In the burning pro- 
cess a union occurs between the carbon and the hydro - 
gen of the fuel and the oxygen of the air. 

Hydrogen in burning with oxygen produces water ; 



no 



DOMESTIC SCIENCE. 



carbon in so combining forms carbon dioxide. Hold 
over a candle flame a dry cold tumbler (figure 52) ; 

water from the flame con- 
denses on the inside of the 
glass. A similar thing oc- 
curs when a cold lamp chim- 
ney is placed in position 
over the freshly lighted wick. 
Soon, however, tumbler and 
lamp chimney become so 
Fig 52. warm as not to allow the de- 

Moisture formed by tlie caudle position of water, 
flame, condensing on a cold 




jSTow arrange an apparatus 
The gases rising from the 
burning candle are drawn through the bottle, in which 



tumbler. 
as shown in figure 53. 




Fit?. 5.H. 
Gases rising from a candle flame, being drawn through lime water. 

is a quantity of clear lime water. This lime water 
soon becomes turbid from the formation within it of 



PRODUCTION OF HEAT. Ill 

insoluble lime carbonate. This, it will be remenabered, 
is a proof of the presence of carbon dioxide. 

The Jfame of the candle is due to the combustion of 
gaseous matters. Fuels containing large quantities of 
volatile combustible matters burn with large flames ; 
such is the case with resinous woods, soft coals, tar, 
pitch, oils and the like ; while fuels that consist mostly 
of fixed carbon, such as charcoal, coke and anthracite 
coal, burn with a steady glow, but with little flame. 
Indeed, flame may be regarded in all cases as burning 
gas. To demonstrate this fact, let us return once 
more to our candle. When it is burning brightly, blow it 
out by a sudden puff ; a stream of vapor is now seen 
rising from the wick ; this consists of the volatile 
part of the wax, which had been carried to the re- 
gion of the flame, but now that the candle is extin- 
guished it cannot burn and therefore it escapes. Now 
apply a light to this rising column of vapor ; the flame 
runs along the line and re -ignites the wick. 

That this combustible va- 
por is produced through the 
action of heat on the wax, 
may be proved by warming 
a quantity of wax in a glass 
tube provided with an es- 
cape jet ; vapor rises and 

Fig. 54. may be burned as it issues 

Combustible vapors of volatilized n ,-, • , ^^ ^,x 

wax. from the ]et (figure 54). 

The hollow nature of the flame may be shown by 

placing a splinter of wood across the flame, as in 

figure 55. A charring action will occur where the 

outer shell of flame touches the wood ; but between 




112 



DOMESTIC SCIENCE. 



these points the wood is unscorched. By deft action 
a match head may be introduced into the flame centre, 





Fig. 55, 

Showing that the candle flame is 
hollow. 



Fig. 56. 
Match head in centre of flame re- 
maining unburned. 



and there held unlighted-, though the heat may be suf- 
ficient to melt the ignition material (see figure 56). 
A strip of paper may be depressed upon the flame, as 

in figure 57. On being 
removed, a blackened 
ring enclosing an un- 
scorched centre will be 
seen. 

The processes operat- 
ing in and about the 
larger flames may be thus 
understood from a study 

Eig. 57. 

Showing that flame is hollow. of the burnmg candle. 
The hydrogen and the carbon of wood and coal unite 
with the oxygen of the air, and in so doing they evolve 
a large and measurable quantity of heat. Fuels are 
etticient in proportion to the amount of hydrogen and 
carbon they contain. All natural fuels, however, con- 
tain a considerable quantity of incombustible matter ; 
the solid portions in the form of ash remain after the 
burniiia'. 




PRODUCTION OF HEAT. 113 

Another cause of diminution in the heating- vahie of 
fuels lies in the amount of water contained by them. 
"We all know that green woods, rich in sap, are far less 
eflScient fuels than are dry woods. Water in fuels 
lowers the percentage of available hydrogen and car- 
bon ; its presence retards the combustive process, by 
absorbing much heat as the burning proceeds ; and 
when the boiling temperature is reached, the water is 
converted into steam, and thus a large amount of heat 
is rendered latent, and is carried off by the escaping 
vapor. 

Woods may be ranged in the following order with 
respect to their heating powers, the poor kinds being 
named first: White pine, poplar, soft maple, cherry,/- 
cedar, elm, hard maple, walnut, beech, apple, ash, 
white oak, hickory. Hydrogen in burning produces 
over three times as much heat as does the same weight 
of carbon. The calorific or heating power of fuels de- 
pends upon the amount of oxygen with which thev 
unite in the course of combustion. Thus, 1 lb. of hy- 
drogen while burning will combine with 8 lbs. of oxy- 
gen ; while 1 lb. of carbon unites with but 21 lbs. of 
oxygen. The practical efficiency of hydrogen as a fuel 
is lowered, however, by the fact that the water pro- 
duced by its combustion absorbs and renders latent a 
large proportion of the heat. The carbon dioxide re- 
sulting from the burning of carbon, having compara- 
tively little capacity for heat, and undergoing no chano-e 
of state, absorbs much less of the heat of combustion. 
For practical purposes, therefore, the proportion of 
fixed carbon in fuels largely determines their relative 
efiiciency. 



114 DOMESTIC SCIENCE. 

Coal exists in many forms, and of widely varying 
degrees of efficiency as fuel. There is much evidence 
to support the view that mineral coal is but trans- 
formed vegetable matter. The remains of many plants 
are found in mines ; the microscope reveals, even in 
the ash of the hardest coal, a cellular structure similar 
to that known to exist in plants ; a substance very sim- 
ilar to coal has been artificially made through the 
operation of heat and pressure upon sawdust and other 
finely divided vegetable matter. Coals are usually 
classified according to the degree of metamorphism to 
which they have been subjected, as shown by the vary- 
ing amounts of volatile matter which they still contain. 
The chief varieties are lignite, cannel coal, bituminous 
coal, semi -bituminous coal and anthracite. 

Lignite, often callecl brown coal, plainly shows the 
woody structure. It is soft and lustreless, and so dif- 
ferent in appearance from the common forms of coal, 
that at first sight one scarcely considers it as belonging 
to the same family. A typical sample from Saxony 
was analyzed by the writer and found to consist of : 
Moisture, 8.24 i)er cent. ; volatile combustible matter, 
49.96; fixed carbon, 38.31; ash, 3.45. 

Cannel coaZ, which in some places is known as pa^rof 
coal, is usually grayish black in color, dense and lus- 
treless. AVhen broken it shows a conchoidal or shell - 
shaped fracture. It contains a tolerably large percent- 
age of volatile matter, and is consequently Avell adapted 
for the manufacture of gas ; in England it is known as 
gas coal. The name cannel is due to a practice still 
followed in Scotland, of using thin pieces of the coal 
in place of candles (Scottish pronunciation — can- 



PRODUCTION OF HEAT. 115 

nels). A good sample of cannel coal from Virginia 
yielded to the author's analysis: Moisture, 0.243 per 
cent. ; volatile combustible matter, 60.818 ; fixed car- 
bon, 35.135 ; ash, 3.882. 

Bituminous coal contains from 40 to 50 per cent, 
volatile matter. This constitutes the commonest class 
of coals. It is a black, lustrous, friable solid, and burns 
with a large flame. Varieties of this coal that are es- 
pecially rich in volatile substances are described as fat 
bituminous coals. A sample of bituminous coal from 
Pleasant Valley, Utah, proved upon analysis to possess 
this composition: Moisture, 4.56 per cent.; volatile 
combustible matter, 39.05; fixed carbon, 54.68; ash, 
1.70. Another variety from Weber County, Utah, 
yielded: Moisture. 8.117; volatille combustible matter, 
42.748; fixed carbon, 46.444; ash, 2.689. 

Coal containing fully 50 per cent, of volatile ingred- 
ients softens much in burning. Such kinds are popu- 
larly called colling coals. 

Semi-bituminous coal contains from 15 to 20 per 
cent, volatile matters. It is richer in hydrogen than is 
anthracite, and it contains more fixed carbon than does 
bituminous coal proper. Owing to its ready inflam- 
mfibility and the comparatively little smoke attending 
its burning, it is in high favor as a fuel for engines and 
boiler fires, and is often called steam coal. 
, Anthracite is a hard, brittle and highly lustrous coal. 
In structure it is very dense, and in breaking shows a 
conchoidal fracture. It may contain upwards of 90 
per cent, fixed carbon, leaving therefore small room for 
volatile ingredients. In burning it evolves great heat, 
but no flame. Coke formed from anthracite differs in 



116 DOMESTIC SCIE^^CE. 

appearance but very slightly from the coal itself. In 
different sections of our own country, anthracite is 
popularly known as glance coal, stone coal, and hard 
coal; in Ireland it is commonly called Kilkenny coal; 
in Scotland it is called from its flameless burning blind 
coal. The varieties of coal here named are but the chief 
or typical kinds. Numerous others are known, differ- 
ing in degree from the ones here named. Beside the 
natural fuels certain forms of artificially prepared car- 
bon are also used ; the chief of these are charcoal and 
coke. 

Charcoal is produced from wood by distilling off the 
volatile matters ; it remains after the process as a black, 
brittle solid, containing all the fixed carbon and ash of 
the wood. It has many uses beside those of fuel ; some 
of these will be subsequently referred to. 

Coke results from the distillation of coal. It is 
made in large quantities as a by-product in the prepar- 
ation of coal gas. It is a porous, friable solid, grayish 
in color, and of medium lustre. It is largely used as 
a fuel in metallurgical operations. 

A very convenient and an efficient artificial fuel is coal 
gas. However, the cost of its production and distri - 
butiou prevents its use as a heating medium becoming 
general. As furnished by its manufacturers, coal gas 
may be regarded as the partly purified volatile matter 
of coal. Its use is attended by considerable danger, 
owing to its poisonous properties and the explosive 
nature of mixtures of gas and air. Coal gas is in more 
general use as an illuminant, though gas stoves for 
heating purposes are in frequent service. Gasoline 
or vapor stoves are now in common use. They depend 



PRODUCTION OF HEAT. 117 

for efficacy upon the burning of the light vapors of pe- 
troleum, such as benzine and gasoline, between which 
substances, as found in the market, there is very little 
difference other than that of the prices charged for 
them. 

The mode of starting fire is an interesting subject for 
study. In very early times, it is said our ancestors 
developed fire by forcibly rubbing together pieces of 
dry wood ; this method was laborious and its results 
uncertain, though it is still employed among savage 
tribes. An advance was made in the use of flint and 
steel with which to produce a spark, and tinder to be 
inflamed thereby. In the early part of the present cen- 
tury the tinder-box was a household necessity. Sul- 
phur matches, consisting of a globule of sulphur on 
the end of a splinter of dry wood, were used in con- 
nection with the tinder, the low igniting point of 
sulphur making it possible to readily procure a flame 
from the smoldering tinder. The matches of the pres- 
ent day depend for their inflammability upon the pres - 
ence of phosphorus. Common matches are made by 
dipping the bits of wood in melted sulphur, and after- 
wards in a paste of phosphorus, potassium nitrate 
(nitre) and glue. Slight friction inflames the phos- 
phorus ; this ignites the sulphur, while the nitre de- 
composes and furnishes oxygen to aid the combustion. 
The glue forms a hard coating impermeable to air, so 
that the phosphorus within the match head is protected 
from oxidation till by friction the outer layers are worn 
away. In the crackling or explosive matches, potas- 
sium chlorate is used in place of nitre ; such matches 
burn quickly. If a colored match head be desired, a 



118 DOMESTIC SCIENCE. 

pigment, usually vermillion, red lead, or Prussian blue 
is stirred into the paste. 

Manj^ serious results have followed the accidental 
ignition of matches, and as a partial safeguard safety 
matches were invented, though their use has not become 
general. Safety matches are capped with a mixture of 
potassium chlorate, antimony sulj^hide, and glue ; they 
ignite only when rubbed on a prepared plate contain - 
red phosphorus and fine sand or powdered glass. The 
red or amorphous phosphorus is far less dangerous than 
is the ordinary waxy phosphorus. 



HOUSE WARMING. 119 



CHAPTER 12. 

HOUSE WARMING. 

'^PHROUGHOUT the temperate and colder regions of 
JL the earth, man finds it necessary to employ means 
for artificially warming his home. In this he aims to 
secure an indoor temperature which will give comfort 
and be conducive to health. No exact temperature 
can be definitely named as being under all circum- 
stances most advantageous. The bodily susceptibilities 
and requirements of different persons for heat vary 
considerably, a middle-aged vigorous man may find 
no discomfort from cold in a room heated only to 59 
or 60 degrees, while an enfeebled or sickly person may 
shiver at 70°. It is evidently advisable, therefore, that 
a medium temperature should be secured, and the indi- 
vidual peculiarities be met as[nearly as possible by suit- 
able amounts of clothing. For the majority of human 
beings, a house temperature of 02° to 68° will be found 
most agreeable and beneficial. 

Many methods of warming dwellings are known, of 
these the open Jire-place properly claims our first atten- 
tion, by reason of its great antiquity. Among ancient 
nations the open fire was the only known means of 
house warming, and the primitive fire-place was a very 
crude affair. The chimney even is a modern invention, 
being now but about 600 years old. Before the 13th 
century, dwellings were warmed by a method which is 
still exemplified in the huts of the Esquimaux — the fire 
being on the floor near the middle of the room, and 



120 DOMESTIC SOll*>NCte» 

the smoke escaping as best it may by the doorway and 
through a hole in a roof. 

Even among the classical Greeks and Romans, but 
little real advancement was made over this primitive 
and dirty practice. It is true tliey had vessels specially 
provided as fire -holders ; these were known as braziers, 
and consisted each of a pan mounted on a tripod of 
convenient height, the whole being ornamented mth 
carving and symbolical devices.* 

The invention of chimneys was soon followed by 
that of fire-places proper. The first of these consisted 
of a huge square opening in the wall ; but a small part 
of this space, however, was actually used for the fire^ 
the remainder being occupied by seats along the sides. 
Count Rumford pointed out some of the many defects 
of such a structure ; he showed that the jambs or side 
walls, if built so as to directly face each other, that is, 
at right angles to the back of the fire-place, would 
simply reflect the heat rays back and forth between 
them ; whereas, if the walls were placed at a widening 
angle with the back, according to the laws govern- 
ing the reflection of rays of force, much of the heat 
and light would be thrown into the room. He con- 
cluded that the best angle at which the jambs could be 
set was 135° with the back of the hearth. 



* Dr. Youman says of the Roman fire-place: "They (the Greeks and 
Romans) kept fires in open pans called braziers. Those of the Romans 
were elegant bronze tripods, supported by carved images with a round 
dish above for the fire. A small vase below contained perfumes, odor- 
ous gums and aromatic spices, which were used to mask the disagree- 
able odor of the combustive products. The portions of the walls most 
exposed were painted black, to prevent the visible effects of smoke, 
and the rooms occupied in winter had plain cornices and no carved 
work or mouldings, so that the soot might be easily cleared away." 



ttousfc Warming. 121 

The modern fire-place is by comparison a dwarfish 
structure ; the open space leading into the chimney 
above the grate is reduced to a minimum, and the grate 
itself is made to project into the room. Much has been 
said in favor of the open grate as a heating device, but 
the fact is undisputed that its use is rapidly declining. 
The brilliant glare of the burning fuel, fully exposed 
to our view, imparts a cheerful influence ; it is in the 
nature of man to love warmth and light, and therefore 
he has pleasant preferences for the open grate — and 
there are many substantial benefits arising from its use. 
The heat derived from a clear open fire is almost en- 
tirely radiant heat, the air of the room never becom- 
ing burnt or excessively heated, and, farther, the fire 
does much to promote efficient ventilation. On the 
other hand, open fire-places are dusty and dirty addi- 
tions to a room ; ashes and soot are sure to escape 
from them into the apartments ; the radiant heat 
warms chiefly the side of persons and objects that is 
directed toward the fire, and in the coldest weather, 
when the efficiency of our heating appliances is taxed 
the most, this inequality of warmth will be found most 
distressing. In addition, open grates do not secure to 
the room a uniform temperature ; but very inadequate 
regulators ofthecombustion,such as dampers and valves, 
are provided, and the varying intensity of the burning 
when the fuel in the grate is low and is then replen- 
ished, will effect rapid chahges in the temperature of 
the room. As regards economy of fuel, nothing can be 
said in favor of the open hearth ; experience has demon- 
strated that the best grates of modern construction 
allow fully 70 "per cent, of the heat to escape up the 



12 -2 DOMESTIC SCIENCE. 

chimney, and in poorly constructed grates the propor- 
tion of loss may reach even 90 per cent. 

In England, the open grate remains still in general 
use, and some improvements are there being intro- 
duced. The following features are considered by many 
English authorities (notably Parkes and Teale) as es- 
sential in good fire-places: The back of grate should 
be about one-third as vride as the front; the sides set 
at the angle of 135° ; the sides and back should be of 
fire brick ; the back should be inclined forward, that 
the flames may play upon it, the whole fire-place 
being carried well forward into the room. The chim- 
ney throat should be narrowed as much as possible, 
and the fire-place and chimney should be built in the 
inner walls of the house, so that the escaping heat 
may do some good in warming the upper rooms. 

Stoves of various forms are now in common use for 
domestic warming. A stove may be described as a 
box, usually of metal, so constructed as to favor the 
combustion of fuel placed within it, and allow the 
ready removal of the gaseous products of the burning. 
Stoves communicate heat to the room, partly by radia- 
tion but mostly by convection. The air in contact 
with the heated surface becomes warm, in consequence 
of which it rises and gives place to a quantity of 
colder air. The air of these rising currents coming in 
contact with the colder ceiling and walls, contracts and 
sinks ; thus circulating currents are created within the 
room. The pipe which leads from the stove to the 
chimney opening imparts much heat to the room ; and 
this effect is materially increased if elbows are placed 
in the pipe. The reason for this is simpl'e — the cooling 



HOUSE WARMING 



123 



Ihf .fo-Hxits \ 



Opt nines under 




OpeniTtas for Cold J' ' 



Double-case stove. 
of the heated gaseous contents of the pipe can occur 
only at the surface of the column ; such process will be 
necessarily slow, and much of the heat will be carried 
to the chimney, whereas, if the current be broken up 
as by passing it by angles in the pipe, a circulation 
within the moving column will be caused, and more 



124 DOMESTIC SCIENCE. 

air will come in contact with the pipe walls, thus allow- 
ing more heat to escape into the room. Figure 58 
illustrates the essential parts and action of the double - 
case stove. 

Stoves, are of but slight appreciable benefit in room 
ventilation, indeed, it is said to their discredit that they 
are of actual detriment through allowing the escape of 
injurious gases from the fire. In stoves of poor con - 
struction, and in the best of stoves badly managed, 
this charge is certainly well founded ; but good stoves 
under efiicient control are not necessarily as detri- 
mental to health as has been claimed. However, if the 
iron walls of the stove become too highly heated, pois- 
onous gases, especially carbon monoxide, will escape 
from the fire into the room. Hot iron, especially if it 
be cast iron, is readily permeable to the deadly carbon 
monoxide, as also to other gaseous products from the 
fire box. Heated iron surfaces are apt to char the 
organic impurities of the air that come in contact 
therewith, imparting to it a foul smell, and other in- 
jurious properties. These ill effects may be prevented 
in a great measure by using stoves with large radiating 
surfaces, so that no necessity exists of over -heating 
any part. The fire-box of heating stoves should be 
surrounded by fire brick or other non-conducting ma- 
terial : such a casing would assist in regulating the 
temperature changes resulting from the varying inten- 
sity of the fire. Another decided disadvantage attend- 
ing the use of stoves lies in the consequent dryness of 
the atmosphere. As air becomes warmed, its capacity 
for moisture increases, and the relative humidity of the 
air is greatly diminished. This may be partially Qver- 



HOUSE WARMING. 125 

come by placing open vessels of water on the stove or 
about the room. Though the use of stoves is attended 
by many serious disadvantages, it is safe to say that 
their demerits have been in some cases over- stated to 
the raising of a strong popular prejudice against them. 
Good stoves may be so operated as to be of far better 
effect than are open grates of best construction if inju- 
diciously managed. 

By the use of anthracite coal stoves it is possible to 
retain a fairly constant temperature even for days. 
Such stoves, if large and well supplied with draught- 
valves and dampers,* may be used with great success ; 
and are well suited to houses of medium size, in which 
no appliances exist for the more efficient methods of 
steam and water warming. 

With all the heating arrangements thus far described, 
the upper parts of the rooms will be warmer than the 
floors, which condition is directly opposite to the re- 
quirements of health ; cold feet are the precursors of 
many forms of illness. The methods yet to be referred 
to promote the distribution of heat at the floor. 

Warmed air is extensively used as a medium in 
house heating. Fresh air from without is carried to the 
furnaces by means of pipes : there it is raised to the 
proper temperature; thence it is carried through dis- 
tributing pipes to the rooms to be warmed, and then 
discharged through register apertures in walls and 



* The method of placing a damper or regulating valve in the pipe is 
a bad one, since when such a valve is closed the gaseous products of 
combustion will surely be thrown into the room. The draught regulators 
should be so placed as to control the admission of air to the fire, not 
arranged to check the escape of gases. 



126 DOMESTIC SCIENCE. 

floors. The most serious defect of the warm -air sys- 
tem lies in the fact that the air becomes relatively dry, 
being in some cases actually scorched, and consequently 
tainted from the charring of the contained organic 
matter. 

Steam-warming is held in high favor as a means for 
heating dwelling houses and large buildings. The es- 
sential features of the process are these : steam is gen- 
erated in a properly constructed boiler ; the vapor is 
conveyed through pipes to the apartments that are to 
be warmed ; there the steam is passed through one or 
more radiators, consisting of a pipe arranged in many 
parallel sections. In condensing, the steam imparts its 
heat to the air of the room. The latent heat of vapor- 
ization has been already explained, (see page 105) It 
will be remembered, that in passing from the liquid 
state at the boiling temperature (212° F. or 100° C.) 
to steam at the same temperature, 537 times as much 
heat is absorbed as would be required to raise the tem- 
perature of the same amount of water 1° C. This 
latent heat, though not measureable by the thermome- 
ter, is retained by the steam and in the condensation 
of the latter, the whole amount of heat will be again 
liberated. Thus water may be vaporized in the cellar, 
and the steam be made the carrier of heat into the most 
distant parts of the house. How admirable is the 
operation of this principle ; how cleanly, efficient and 
economical is this method over that of grates or stoves 
in rooms, with their inevitable accompaniments of dust 
and dirt, irregular temperature, uncontrollable draughts, 
woeful waste of energy ! The boiler may be situated at 
anv reasonable distance from the ¥ooms to be warmed. 



HOUSE WARMING. 127 

If far removed, however, it is necessary to protect the 
pipes with coatings of non-conducting material, else 
much heat will be lost on the way. The conducting 
pipes are usually wrapped with many layers of asbestos 
fibre ; then with hair felt, and outside of this with several 
thicknesses of stout paper ; on this strips of wood are 
laid lengthwise and the whole is bound together by 
wire. The pipe thus wrapped is enclosed in a wooden 
tube, usually a hollowed log. Such insulation is not 
needed in small buildings, or in any case wherein the 
pipes are not exposed for any great length. 

The warming of houses through the medium of warm 
ivater depends for its efficacy upon the high specific 
heat of water (see page 106), by virtue of which it ab- 
sorbs for a given rise of temperature a greater amount 
of heat than does any other liquid, and in cooling 
through a given range of temperature a correspond- 
ingly large amount of heat is given out. 

In the loiv pressure system of heating by water, the 
pipes are so connected with the boiler as to allow a 
complete circulation ; the water returning to the boiler 
after having traversed the circuit of pipes. From the 
highest point in the course of the pipes a vent is pro - 
vided for the escape of steam and heated air. The 
water in this system can never exceed in temperature 
the boiling point — 212° F., and therefore no scorched 
or excessively^ry state of the air is possible. 

The method known as the high pressure system re- 
quires the use of very stout pipes without a vent. No 
boiler being used, the pipes pass directly through the 
furnace, and no escape is provided ; the enclosed water 
becomes heated under pressure ; its temperature may 



158 DOMESTIC SCIENCE. 

therefore be raised far above the ordinary boiling 
point ; still, as there is no room for expansion ^ steam 
is not produced. In this system the water may be 
heated above 300° F. 



LIGHT AND LIGHTING. " 129 



CHAPTER 13. 

LIGHT AND LIGHTING. 

DURING the daytime we depend for light directly 
upon the rays that come to us from the sun ; this 
we call natural light ; throughout the dark hours, we 
adopt various means for the local production of light ; 
this we call artificial light. In reality these terms 
are misleading ; the light of lamp and candle is natural 
light; it results from the combustion of various ani- 
mal and vegetable matters, all of which grow under 
the influence of the sun's energy. 

Daylight is free to all ; we are only required to pro- 
vide for its admission to our homes. It is not doled 
out to us by the pound or the quart; no company's 
agent calls to read the metre and prepare the bill of 
our indebtedness. Light, the purest and the best that 
the physical eyes of man have ever come to know, is 
showered with a Creator's liberality upon the world. It 
floods all places that are open to it. Yet how careless 
we grow as to its distribution and use ! Physiologists 
declare to us that light is as essential as is warmth to 
the welfare of the body. Our homes then should be 
well lighted. 

It is true that the delicate organs of sight may be 
seriously impaired through exposure to light of un- 
usual brilliancy ; though the eye strain induced by de- 
ficient illumination, is a far more frequent cause of sight 
deterioration. The illumination within dwelling rooms 
should be such as to produce in the eye a feeling of 



130 DOMESTIC SCIENCE. 

ease and comfort; no strain should be experienced 
when closely viewing any object within the range of 
vision. For a person sitting at the table reading or 
writing, the light should come from above as through 
a skylight, or from the left and back. In this way 
the paper or book is well illuminated, and the shadow 
is thrown away from the right hand. 

For artificial illumination, the methods most com- 
monly employed depend upon the combustion of cer- 
tain substances, whereby a luminous flame is produced. 
An exception to this is seen in the case of the electric 
light. 

As has already been stated, flame is the result of 
the combustion of gases ; solid fuels may evolve great 
heat and yet their combustion is flameless. Yet many 
flames are but slightly luminous ; for example, hydro- 
gen burning with a very intense heat emits but a very 
feeble light. - The flame of the common spirit lamp, 
depending upon the combustion of the vapor of alcohol, 
is almost entirely non -luminous. The luminosity of 
flame is due to the incandescence of solid particles 
which are present with the gas. The most intense 
artificial lights are produced by the incandescence of 
solids. Many of the carbon particles in the candle 
vapor are heated to incandescence, the supply of oxy- 
gen is insuflScient to burn them with undue rapidity ; 
they therefore shine. In an ordinary flame (figure 59) 
several distinct parts are discernible ; (a) a dark, 
central core, in which region no combustion is possi- 
ble because of the absence of air; (b) a luminous 
cone; and (c) an outer envelope. 

Figure HO represents an ordinary mouth blowpipe; 



LIGHT AND LIGHTING, 



131 



such as is used by jewelers, chemists and others. By 
means of such a pipe, additional air may be blown 




Fig. 59. 
Parts of candle flame. 



Fig. 61. 
Blowpipe flame. 



into the flame; the flame then be-^ 
comes a solid one, the combustible 
materials are more rapidly and com- 
pletely burned ; few solid particles 
have time to become incandescent be- 
fore they are consumed ; the result is 
a bluish, hot, but iion -luminous 
flame. In flgure 61, a represents 
the end of the blowpipe inserted in 
the flame. 

There was a time, and that within 
the memory of the middle-aged 
among us, when candles were the 
commonest of household illuminants. 
The structure of candles and the 
general nature of their flame have been already 
noticed. The place of candles in domestic lighting 




Fig. GO. 
Moutli blowpipe. 



132 



DOMESTIC SCIENCE. 




Fig. 62. 
Simple form of lamp. 



has now been taken by Ja7nps in which certain 
inflammable oils are burned. 

A lamp of modern construction (figure 62) con- 
sists essentially of a cistern, h, 
for holding oil ; supported on a 
base or pillar, a ; a wick, c, for 
conveying the fluid to the place of 
burning ; a burner, e, for the sup- 
port of the wick and the proper 
distribution of air about it ; this 
is usually provided with a rachet, 
d, by which the wick may be 
raised or lowered ; and a chimney 
of glass, /, to shield the flame 
from the disturbing effects of 
draughts. The wicks that were first 
made were shaped like a solid cylinder ; those of later 
times are flat. Dr. Franklin demonstrated in the case 
of candles, that two small wicks burned side by side 
gave greater light than would a single wick of double 
size ; this fact is due to the greater surface exposed by 
the double wick. The advantage of spreading out 
the wick fibres thereby enlarging the surface will be 
readily seen. 

About 1790, A. D., one Argand, of Geneva, in- 
vented a lamp in which the wick was arranged as a 
hollow cylinder ; this is still in use, and is known as 
the Argand lamp. The general features of this lamp 
will be understood from an inspection of figure 63, 
which shows the complete lamp, and a section of the 
same. With such a wick a large circular flame is 
produced ; by a peculiar construction of the burner 



LIGHT AND LIGHTING. 



133 



air is iutroduced into the interior of the flame, so that 
a more perfect combustion with a consequent increase 
of light is the result. The wick may be raised or 
lowered so that the size of the flame will be pro- 
portional to the air current. A valuable improvement 
on the original Argand lamp was made by Lange, a 
Frenchman. He proposed a narrowed chimney tube, 




Fig. 63. 
Argand lamp and section of same. 

one having a shoulder in the region of the flame. The 
effect of such a chimney is to deflect the outer air 
current upon the flame, whereby an increased efii- 
ciency is secured. 

With a lamp of this construction it is possible to 
burn without difiiculty the heavier and poorer oils, be- 
cause the free supply of air favors a very complete 
combustion of the carbon without the production of 



134 DOMESTIC SCIENCE. 

smoke. The Argand lamp is noted for the steadiness 
of its flame ; it is well adapted to the writing table, 
and is commonly and appropriately called the student's 
lamp. 

The reservoir of oil is set on the side so as to be 
safely removed from the heated region of the flame. 
The reservoir proper is inverted in an outer vessel, 
and the contained liquid is held in position through 
pneumatic pressure, and is conveyed to the wick only as 
fast as used. 

A serious objection to the use of the Argand lamp 
for general illumination is based on the shadow thrown 
by the oil reservoir. The cistern of common, flat- 
wick lamps is sometimes so shaped as to throw an 
objectionable shadow. The larger the cistern is the 
more extensive will be its shadow ; yet small oil 
holders are objectionable, because the level of their liquid 
contents falls rapidly as the burning proceeds, thus 
increasing the distance between the oil and the burner, 
with a consequent diminution of the supply through 
the wick, and a very marked decrease of light. 

Many forms of hollow wick lamps are now in the 
market. The appearance and construction of an 
efficient kind may be understood from flgure 64. 
The large wick is placed around the hollow cylinder, 
through which air is carried from below. The base at 
its place of support is either scalloped or perforated, 
so as to allow the ready passage of air into the central 
channel (a). A funnel-shaped distributor deflects the 
inner column of air against the flame. Lamps of this 
construction afford much light ; they are not well 
adapted for the writing desk or reading table because 



LIGHT AND LIGHTING. 



135 



of the great heat resulting from the large consumption 
of oil. 

It is advisable to surround the lamp chimney with a 
convenient shade, so as to moderate the intensity of 
-the rays that reach the eye. It is not desirable that 




Fig. 64. 
Hollow-wick lamp. 

light pass in an unbroken line from its source to the 
eye ; its efficiency depends upon the illumination of 
the objects to be viewed ; and experiment has 
demonstrated that if the eye in viewing an object re- 
ceives from other sources any rays of light of greater 
intensity than those reflected from the object, the usual 
impression is weakened, and the organ of sight is un- 
naturally strained. The value of a shade in deflecting 
the light downward upon the table will be readily 
seen. The best shades are made of ground glass or 
porcelain, and are colored on the inside sky-blue. 
Artificial light from candles or oil lamps is deficient in 



136 DOMESTIC SCIENCE. 

certain of the component colors of white light, and 
the blue shade will partly supply the missing tints. 
Shades so colored give less intense but purer illumina- 
tion. 



COMMON ILLUMINANTS. 137 



CHAPTER 14. 

LI(;HTIN(i continued: common ILLUMINANTS. 

REFERENCE has already beeu made to caudles as 
sources of light, let us uow cousider other illum- 
iuauts. 

Among the common illuminating fluids, are fish 
oil, lard oil, colza oil, turpentine, and kerosene. The 
last named is the common household illuminator. 
Kerosene is a product of the distillation of petroleum, 
and, as offered in the market, is of specific gravity lower 
than that of water, clear and transparent, the best grades 
showing a blue tint by reflected light. 

In burning, the oil is first converted into vapor ; this 
takes fire at a temperature which varies for different 
kinds of oil ; this degree of temperature is known as 
the Jiashin.g point ; at a somewhat higher temperature 
the liquid burns continuously, this is known as they're 
test point. Evidently the use of oil of a low flashing- 
point is attended by great danger from the liability of 
the mixture of air and vapor within the oil cylinder 
to explode. In many parts of the United States and 
in Europe, there are legal enactments specifying the 
lowest flashing point that is permitted in oils offered 
for public sale. The writer has found in the market 
varying grades of kerosene, of flashing points ranging 
from 75° F. to 135° F. ; and of fire test as low as 110° 
F., and as high as 300° F. 

6 



138 DOMESTIC SCIENCE. 

The stringency of the laws has done much to restrict 
the sale of light oils ; and it is pleasing to contemplate 
that accidental explosions in lamps are now infrequent. 
With the best of oil, however, careless management of 
the lamp may lead to disastrous results. The common 
practice of extinguishing the flame by blowing down 
the chimney often causes an ignition in the oil chamber, 
in which case an explosion is almost inevitable. Allow- 
ing a lamp to burn itself out, is a dangerous practice. 
The wick smoulders, and a spark or a glowing ember 
may reach the oil chamber, and cause a destructive ex- 
plosion. Some improved forms of lamps are provided 
with extinguishers ; and others have an automatic 
attachment by which the flame is put out if the lamp be 
overturned. With the best of contrivances, and under 
the most favorable conditions, great care in the manage- 
ment of the lamp is essential to safety. 

Coal gas is used in large towns as an illuminant. It 
consists of the volatile matter of coal. The production 
of gas is carried on at the central works, the gas being 
then distributed through underground mains to the 
consumers. Good gas is a cleanly, convenient, and an 
eflScient material for illumination ; though its presence 
in the house entails certain dangers demanding con- 
stant vigilance on the part of the inmates. An acci- 
dental escape of gas into the rooms may form with the 
air an explosive mixture ; and the smallest amount of 
coal gas in the air of the house, must be regarded as a 
poisonous addition. The inhalation of any consider- 
able amount of coal gas produces asphyxia and speedy 
death. It is well for us that the substance possesses a 
disagreeable odor ; for by.it we may often recognize the 



COMMON ILLUMINANTS. 139 

presence of the poison, and we should seek to preserve 
our sensitiveness to its effects. The gas is consumed 
at convenient points along the line of the supply pipes, 
burners of different forms being employed, named 
from the shape of the flame produced by them ; the 
commonest burners are the fishtail, the bat's -wing, 
and the Argand. Gas burners may be provided with an 
electric attachment, so that the passage of a current from 
a local battery opens the valve, thus allowing the gas 
to pass, and ignites it as it issues. With such a con- 
trivance, it is only necessary to press the current button, 
Avhich may be located in any convenient place, and the 
gas is turned on and lighted. A second push stops 
the flow of gas, and, of course, extinguishes the 
light. 

Water gas is the name of another illuminant, which 
is produced- by the decomposition of steam through 
contact with incandescent carbon. The oxygen from 
the steam unites with the carbon to form carbon mon- 
oxide, while the hydrogen of the steam is freed. Such 
a mixture of hydrogen and carbon monoxide burns 
with considerable heat, but with little light ; it is 
necessary therefore to enrich the gas, and this is 
accomplished by mixing it with the vapors of naphtha, 
gasoline, or other highly volatile mineral oils. 

Another method of using the vapors of light oils as 
illuminants consists in passing a current of air through 
such liquids, whereby the air becomes saturated with 
combustible vapors ; in this state it is conveyed through 
pipes to the place desired and there burned in ordinary 
gas burners. The apparatus used in the production of 
this vapor gas is simple and portable, it may be operat- 



140 DOMESTIC SCIENCE. 

ed in any dwelling house. Dangerous explosions have 
occurred from the premature lighting of the vapor 
laden air. 

All the methods of house lighting thus far consider- 
ed possess the serious defect of contributing largely to 
the pollution of the atmosphere. * 

Various forms of ventilator burners have been pro- 
posed ; these are designed to carry away through flues 
the objectionable products of combustion ; but all of 
such contrivances are expensive and inconvenient, and 
none of them have come into very general use. Vitiation 
of the atmosphere is inevitable while illuminative 
methods are dependent upon processes of combustion. 

Such objections are inapplicable in the case of electric 
lighting. Electric lamps are of two kinds, the arc 
lamp and the incandescent lamj^. In the first, 
(figure 65) the light results from the passage 
of a strong current through rods of gas car- 
bon set end to end, which are separated at the place 
of contact. Some carbon particles become volatilized 
through the great heat caused by the current, these 
form an incandescent bridge between the separated rods. 
The arc light is in favor for illuminating streets and 



* Dr. Youmans says:— "A candle (six to the pound), will consume 
one-third of the oxygen from 10 cubic feet of air per hour, while oil 
lamps with large burners will change in the same way 70 feet per 
hour. As the degrees of change in the air correspond with the 
amount of light evolved, it is plain that gas illumination alters the air 
most rapidly. A cubic foot of coal gas consumes from 2 to 2 and a 
half cubic feet of oxygen, and produces l to 2 cubic feet of carbonic 
acid. Thus every cubic foot of gas burned imparts to the atmosphere 
1 cubic foot of carbonic acid, and charges 100 cubic feet with 1 per 
cent, of it making it unfit to breathe. A burner which consumes 4 
cubic feet of gas per hour spoils the breathing qualities of 400 cubic 
feet of air in that time," 



COMMON ILLUMINANTS. 



141 



large buildings ; but for illumination on a smaller scale 
the incandescent lamp (figure 66) is preferable. This 
consists of a globe of glass, sealed, and containing some 
inert gas such as nitrogen or carbon dioxide, which 
will not support combustion. A fine hair- like filament 





Fig. 65. 
Electric arc lamp. 



Fig. 66. 
Incandescent electric lamp. 



of carbon is placed within the globe, the ends connect- 
ing with binding screws to which the line wires of the 
electric circuit can be joined. As the illuminating 
effect is not due to the chemical energy of combustion, 
it is plain that this method of lighting does not result 
in vitiation of the air. Incandescent lamps may be 
operated under water, and in this way aquaria may be 
beautifully and brilliantly illuminated. 



142 DOMESTIC SCIENCE. 

Even the best of our methods of artificial illumina- 
tion are woefully wasteful of energy. This is largely 
due to the fact that much of the energy developed by 
combustion or through electrical resistance, manifests 
itself as heat instead of as light. Lamps are intended 
primarily as sources of light, and not as heating 
apparatus, yet the results of experiments recently re- 
ported (August. 1890,) by Professor Langley, showthat 
99 per cent, of the energy of candle and lamp flames is 
lost as far as illuminating effect is concerned ; and that 
in electric lighting, fully 50 percent, of the total energy 
never appears as light. Experiments are now in pro- 
gress to test various methods of producing light 
with a minimum of loss through heat radiation. Upon 
this subject considerable interest has of late been 
stirred by the phenomena attending the fire-fly's glow, 
and other examples of natural phosphorescence. At 
present, man is unable to produce light equal in 
intensity to that of the fire -fly, without an ac- 
companying temperature of nearly 2000° F. ; yet 
the light -giving power of the insect named is ex- 
ercised without development of sensible heat. 

Referring to his experiments on the fire -fly's light. 
Professor Langley says: "We repeat, that Nature 
produces this cheapest light at aljout one four- 
hundredth part of the cost of the energy which is 
expended in the candle-flame, and at but an in- 
significant fraction of the cost of the electric light, which 
is the most economic light that has yet been devised : and 
that finally there seems to be no reason why we are forbid- 
den to hope that we may yet discover a method (since 
such a one certainly exists, and is in use on the 



COMMON ILLUMINANTS. 143 

small scale), of obtaining an enormously greater re- 
sult than we now do from our present ordinary 
means for producing light." 



144 DOMESTIC SCIENCE. 



P^jPlK.T II. 



WATER. 



CHAPTER 15. 

WATER ITS "OCCURKENCE. 

WATER is indisj)eiisable in many of the processes 
of life ; and in domestic operations it is a prime 
necessity. Without it, the intricate machinery of 
civilization would be inactive ; and all physical forms of 
life, the bodies that serve as tenements for deathless 
spirits, Avould cease to exist. Indeed the structure of 
even the dead things of earth depends largely upon the 
presence of water. 

In each of the three great divisions of created things, 
minerals, plants, and animals, water is present as an 
essential constituent. In Minerals it forms a very 
considerable proportion of the total composition, and 
in many cases gives to the mineral bodies their character- 
istic color and form. To illustrate this, take a crystal 
of copper sulphate, — blue vitriol, or blue stone as it is 
commonly called : carefully heat it in an iron spoon, 
or better, in a clean dry test tube. Very soon, steam 
is seen rising from the crystal ; in the tube this vapor 
condenses on the colder part of the glass, and may 
there accumulate till it gathers in drops and trickles 
down tlie tube in a stream. Now that the water has 



WATER ITS OCCURRENCE. 145 

been expelled, instead of the beautiful, transparent 
"blue stone", we have left only a grayish powder, 
entirely undeserving of the popular name. A drop of 
water added to this powder will partially revive the 
azure tint, but the transparency, and the symmetrical 
form have gone forever. The experiment teaches us 
that the presence of water is essential to the crystal - 
ine arrangement of particles within the mass. A 
transparent piece of alum heated in the same way will 
evolve large quantities of liquid, and will assume the 
appearance of a white, opaque powder — the ""burnt 
alum'- of the druggists. Chemical analysis has proved 
that water is ordinarily present in the minerals named 
below, as specified : 

Per cent, water. 

Calcium sulphate (gypsum) - - 20.9 

Copper nitrate . . . 39.1 

Copper sulphate, (blue vitriolj - - 36.1 

Zinc sulphate (white vitriol) - - 43.9 

Iron sulphate, (gi;een vitriol) - -, 45.3 

Borax . - _ . 47 j 

Soda alum . . - . 47 3 

Magnesium sulphate (Epsom salts) - 51.2 

Sodium sulphate (Glauber salts) - 55.9 

Sodium carbonate (washing soda) - G2.9 

The common designation of water so combined in 
minerals is "water of crystallization." By mere ex- 
posure to dry air, many of the salts named in the table 
allow some part of the contained water to escape ; 
such process is called efflorescence. To observe this, 
take a few clear crystals of Glauber salts, or of washing 
soda ; put them in an open dish, and set in a warm dry 
atmosphere ; the substance soon loses its transparency 
and becomes opaque and friable. This property of 



146 DOMESTIC SCIENCE. 

solids containing water of crystallization is well known 
to /the dealers in such substances ; grocers and druggists 
usually store efflorescent salts in tight cases so as to 
prevent the escape of the water of crystallization, and 
a consequent decrease in weight. Washing soda if ex- 
posed in open vessels may lose over half its weight. 

Beside the water commonly combined in mineral 
bodies, and forming an essential constituent of the 
same, large quantities of the liquid are sometimes 
absorbed and mechanically retained by minerals. 
Coal frequently contains even ten per cent, of water. 
Ores taken from the mines, though seemingly dry, are 
often so heavily laden with water as to necessitate a 
drying process preliminary to the furnace treatment. 

In the kingdom of Plants, water is no less widely 
distributed nor less essential as an item of their com- 
position. Its presence in vegetable bodies may be 
easily demonstrated. Place within a dry test tube a 
chip of wood, a little saw dust, starch, or any other 
plant product — better select an apparently dry substance, 
that the illustration may be the more impressive ; — now 
apply heat, taking care not to char or blacken the sub- 
stance ; soon water is evolved as steam, this condenses 
upon the cold .portion of the tube. 

The following table exhibits the proportion of water 
in certain fresh vegetable substances, the figures being 
the average results of numerous analyses : 





Per cent, water 


Pine wood 


40 


Timothy 


70 


Meadow grass 


72 


Lucerne 


75 


Potatoes 


75 



WATER ITS OCCURRENCE 



147 



Red clover 
White clover 
Grapes 
Beets 

Apricots . 
Apples 
Carrots 
Gooseberries 
Strawberries 
Cabbage . 
Turnips . 
Cucumbers 
Water melons 



Per cent, water. 
79 
81 
81 

82 
83 
84 
85 
86 
87 
89 
91 
97 
- 98 



Through exposure to the air, part of this constituent 
water will be lost, but even in air -dried vegetable 
products very large proportions of water remain , as 
will be seen from this table ; the figures represent 
average amounts as foundby examinations of numerous 
samples : 





Per cent, water 


Meadow grass hay . . • 


15 


Red clover hay 


16 


Dried pine wood 


15 


Dried wheat straw . 


16 


Wheat kernel 


15 


Indian corn 


13 


Rye kernel 


15 


Barley 


14 


Oats 


13 


Buckwheat . 


13 


Peas 


14 


Rice 


13 



Water is the medium by which the nutritive. matters 
of the soil are carried into the body of the plant. The 
roots of common plants ramify through the soil in great 
abundance ; the main root giving off many branches, 
which in turn divide, and subdivide till they become 
finer than hairs. 



148 



DOMESTIC SCIENCE. 



The root hairs are in close contact with the soil ; so 
close indeed that in many cases it is possible to separate 
the adherent soil from a root that has been taken from 
the ground, only l)y vigorous shaking and thorough 
washing. 

Figure 6 7 (right sketch) shows the appearance of a 
wheat rootlet with adhering soil just as it was taken 





Fig. 67. 

Rootlet with rootliairs ; rootlet 

with adhering soil. 



Fig. 68. 

Pressure guage attached to a 

growing plant. 

from the earth ; and the left sketch exhibits the same 

after thorough washing to remove the soil. The 

numerous root -hairs are distinctly shown. Through 

the roots, large quantities of water are absorbed. 

The liquid rises through the vessels of the stem in the 

form of sap, and in doing so exerts a surprising force. 

There is a method of forcibly demonstrating this (see 



WATER— ITS OCCURRENCE. 149 

figure 68). If a pressure guage consisting of a bent 
tube 6, with mercnry in the bulb c, be attached to the 
stem of a growing plant a cut off near the ground, the 
rising sap will lift the column of mercury. In an 
operation of this kind, Dr. Hales found that the pressure 
exerted during the spring of the year by a young grape 
vine supported a column of mercury 32^ inches high. 
This corresponds to a column of water 36^ feet in high 
or to a pressure of 16^ pounds to the square inch. 
Hofmeister found that a common stinging nettle simi- 
larly tested, supported a column of mercury 14 inches 
high, due to a pressure of 7 pounds per square inch. 
The water so absorbed is distributed throughout the 
entire structure of the plant ; many of the solid matters 
which enter the plant in solution are retained within 
the vegetable cells ; while the water itself escapes through 
the countless stomata of the leaves. 

In the bodies of Animals water abounds. A very 
large proportion of the meats, eggs, and milk we buy 
is water ; this will be seen from the following table : 







Per 


cent, water. 


Fresh mutton contains 


- 


71 


" beef 


- 


- 


73 


" veal 


- 


- 


75 


'" pork 


- 


- 


7G 


" flsh 


- 


- 


80 


" fowl 


- 


- 


73 


" egg 


- 


- 


74 


" milk 


- 


- 


87 



The bodies of many of the lower animals consist 
mainly of water. Agassiz, a scientist of high repute, 
examined the body of an aurelia or sun fish, from the 
Atlantic coast of this country ; when alive the creature 



150 



DOMESTIC SCIENCE. 



weighed 30 lbs., but when thoroughly- dried its body 
yielded but half an ounce of solid matter, — showing 
over 99.8 water. 

It has been proved that the average human body 
contains water to the extent of from two -thirds to three - 
fourths of its weight. The proportion of water present 
in different organs of the body will be seen from the 
following exhibit : 





Per cent, water 


Human teeth 


10 


,, bones 


13 


muscles 


75 


,, brain 


79 


,, blood 


79 to 80 


„ bile 


88 


,, milk 


88 to 89 


„ gastric juice 


97 to 98 


,, perspiration 


98 to 99 


„ saliva 


99 to 99.5 



To supply the body with the requisite amount of 
water, a man of average size has to imbibe about three 
and a half pounds of the liquid daily ; this would 
amount in a year to over 127 gallons. It is not 
necessary that this quantity of water be actually drunk, 
as a very large part of it is supplied from the food. 



WATER SOME OF ITS USES. 151 



CHAPTER 16. 

WATER SOME OP ITS USES AND PROPERTIES. 

ASIDE from forming so extensive and important a 
constituent of minerals, plants, and animals, the 
uses of water are many and varied. In each of its 
three physical states, as a liquid (water itself), as a 
solid (ice), and as vapor (steam), it proves of inesti- 
mable service to man. 

In the form of running streams it furnishes us a 
continual source of power. Each tiny drop pushes 
against the wheel, and the current grinds our corn 
and weaves our cloth ; drives our saws and planes, 
and forces open the vaults in which Nature has stored 
her wealth of sugar and nectar, of oil and of wine. In 
its ocean depths it forms an efficient and easilj'^ used 
road of travel between distant lands ; and in both 
stream and sea it constitutes a home for countless 
forms of animal life of value to us for food and orna- 
ment. 

As ice, it is to us a cheap and an effective protection 
against decomposition ; it stands guard over things 
most perishable, and successfully repulses the ever 
eager spirits of decay and destruction. In this form, 
too, it is held in reserve upon the mountain tops till 
its presence is most needed on the fields and farms be- 
low ; and then, bursting away its frozen bands, it 
hastens down with a merry babble and a joyous laugh, 
like the voice of a happy child awakening from peaceful 



152 DOMESTIC SCIENCE. 

dreams to pleasant play. It carries joy and comfort 
in its course ; the thirsty plants lift up their heads at 
its approach and smile with thankfulness ; the laden 
beast is refreshed, and the heart of man is gladdened. 

As steam, it propels the wheel of civilization, and 
has done much to put the stamp of progress upon the 
present age, and to establish the superiority, of God- 
given mind, over all else upon earth. Its effects have 
surpassed the ac^hievements of the fabled giants of old, 
who were said to run a mile at a stride, and to carry 
houses upon their backs.* 

In physical properties, water is the perfection of 
adaptability to the needs of man. In the most of its 
characteristics, it is the type of neutrality, odorless, 
without color, and devoid of taste. High flavors and 
sweets are not always pleasant to the palate, and the 
most subtle perfumes are at times sickening and even 
injurious in their effects. If water possessed positive 
properties of taste and smell, all our foods, into the 



* "Water is the common carrier of creation. It dissolves the ele- 
ments of the soil, and, climbing as sap up through the delicate 
capillary tubes of the plant, furnishes the leaf with the material of its 
growth. It flows through the body as blood, floating to every part of 
the system the life-sustaining oxygen, and the food necessary for 
repairs, and for building up the various parts of the 'house we live in.' 
It comes in the clouds as rain, bringing to us the heat of the tropics, 
and tempering our northern climate, while in spring it floats the ice of 
our rivers and lakes away to warmer seas to be melted. It washes 
down the mountain side, levelling its lofty summit, and bearing 
mineral matter to fertilize the valley beneath. It propels water- 
wheels, works forges and mills, and thus becomes the grand motive 
power of the arts and manufactures. It flows to the sea, bearing on its 
bosom ships conducting the commerce of the world. It passes through 
the arid sands, and the desert forthwith buds and blossoms as the 
rose. It limits the bounds of fertility, decides the founding of cities, 
and directs the flow of trade and wealth." 

Du. Steelk. 



WATER SOME OF ITS USES. 153 

composition of which water so largely enters, and in 
the cookery of which it plays so important a part, 
would partake of the universal llavor, their qualities 
would be in all cases modified, and in many instances 
destroyed thereby. 

The properties of water under the influence of heat 
have been dwelt upon in a preceding chapter. Its high 
specific heat, whereby its temperature changes are 
modified and retarded, the great amount of hea 
rendered latent in the fusion of ice and in the formation 
of steam, with some of the resulting good effects have 
also received attention. 

In passing from a liquid to a solid form, that is in 
freezing, water observes a strange and an anomalous 
behavior. Solidification, or freezing, is the result of 
cooling, and is usually attended by contraction in bulk. 
The principle that "heat causes expansion and cold 
causes contraction," applies to water at certain tem- 
peratures only. Above 4° C. or 39.2° F., water ex- 
pands by heating : below that temperature it expands 
by cooling ; so that a piece of ice is larger than the 
mass of water from which it was produced. The ice 
is therefore specijically lighter than the water ; and as 
a consequence ice floats in water. If the contraction 
of water by cold continued to the point of congelation, 
there would be a constant rise of warm, and a fall of 
cold water in the body of the liquid undergoing the 
freezing process, till the whole would become solid, and 
in the case of alake, sea or ocean, all living things therein 
would be killed. Farther, — if ice sank as fast as 
fornaed in lakes and seas, it would be beyond the 
reach of the sun's rays, and many tropical summers 



154 



DOMESTIC SCIENCE. 



would be required to thaw the ice of one temperate 
winter. As it is, however, ice being a poor conductor 
of heat, the surface layer actually protects the warmer 
water below from undue cooling. 

By reason of the expansion of freezing water, frost 
is a most valued servant to the farmer, breaking up the 
hardened clods, and exposing large surfaces of soil to 
the vivifying action of tho air. In an analogous way 
the rock -masses of the hills are burst asunder, and 
thus they are prepared for rapid disintegration and 
speedy conversion into fresh and fertile soils. 




Fig. 69. 
Crystals of ice. 

Freezing is essentially a crystallizing process, and 

the microscope will reveal in the snow-flake and the 

ice block a symmetry of parts analogous to that of the 

stony crystals of earth. The unaided eye perceives the 

beauties of the hoar frost on pavement and window 

pane ; the glistening spangles suggest flowers, fruity and 



WATER SOME OF ITS USES. 155 

leaves ; surely the winter is not without its flora. To 
examine the snow flowers microscopically, choose a 
cold day when comparatively dry flakes are falling ; 
catch them upon cold pieces of colored glass ; do not 
touch them or breathe upon them ; then examine with 
a low magnifying power. Figure 69 shows a very few 
of the almost infinite forms of the crystals of frozen 
water. Each of them is composed of six main parts or 
groups of parts, all arranged upon a plan of seeminglj^ 
perfect symmetry.* The prevailing angle at which the 
spangles are set with regard to each other is the same 
in all. Why this constancy? Surely the Great Creator 
delights in order ; and we His children can at least 
learn to appreciate the beauties of His wondrous work- 
manship. 

It would be difficult to find a substance that does 
more than water does in beautifying and diversifying 
the surface of our earth and its surroundings. The 
heavenly tints of morn and eve, the glorious bow, 
which seals the covenant of the Creator with his chil- 
dren, and which must ever remain an object of our 
deepest wonder and admiration ; the varying effects of 
cloud and mist — all are largely due to the water drops 
suspended in the air. The pretty spangles of the hoar 
frost, the ferns and leaves of the winter window, the 
stars and flowers of the snow flake and the ice block, 
show the operations of the building forces of Nature 
according to the laws of strict and perfect science. 

* Professor Tyndall describes a certain fall of snow crystals wit- 
nessed by liim as " a shower of frozen flowers; all of tliem were six- 
leaved ; some of the leaves threw out lateral ribs like ferns ; some were 
rounded, others arrowy and serrated ; but there was no deviation from 
the six-leaved type." 



156 DOMESTIC SCIENCE. 



CHAPTER 17. 

SOURCES OF WATER. 



IN view of the many and diverse uses of water in the 
operations of life, it is gratifying to note that Nature 
has supplied it in unstinted quantity, liberally distrib- 
uted throughout the world. The water we use is pri- 
marily derived from the clouds, through the medium 
of rain and snow fall. A part of the water that falls 
upon the surface of the earth speedily returns to the 
vaporous condition, and is again lifted into the atmos- 
phere. The inclination of the ground surface and the 
nature of the soil with respect to its permeabilit)^ to 
liquids, will determine what proportion of the re- 
mainder will run off in the form of streams, and what' 
part will sink and percolate through the soil. That por- 
tion of the surface water that flows away in streams goes 
to swell the rivers of the neighborhood ; and a part of 
that which sinks into the soil serves to supply the roots of 
growing plants ; the rest of the percolating water will 
probably reappear at some distant place in the form of 
springs. In the case of porous soil, this percolation is 
rapid, so that in some regions it is found necessary to 
collect the rain water in cisterns as it falls, and store 
it for general use. 

Rain ivater is especially serviceable for many house- 
hold operations on account of its softness, which is a 
result of its freedom from mineral impurities. To 
procure pure rain water, the collection should be made 
in an open space ; the water that comes to us from the 



SOURCES OF WATER. 



157 



roof pipes is usually almost black from the impurities 
that it has washed from the roof. 

Much of the water that serves our domestic purposes 
is derived from springs. These are numerous in hilly 




Fig. 70. 
Hillside spring. 



regions, providing the rainfall is adequate and the soil 
of proper kind. As the water falls from the clouds 
upon the hills, a part of it sinks into the soil and des- 
cends till it reaches a stratum that is impermeable to the 




Fig. 71. 
Fissure spring b, and artesian well c. 

passage of water. Here its downward course is 
checked, and the water flows along the impermeable 
layer as along a floor. If this should lead it to the 
surface of a hill, there the water will issue as a hill -side 



158 



DOMESTIC SCIENCE. 



spring (see figure 70). If, however, the course of the 
floor -stratum should be such as to carry the water be- 
low the land surface in the valley, (as illustrated in 
figure 71) the liquid may continue beneath the earth 
till it finds or forms a fissure in the earth ; from this it 
escapes as a fissure spring, or main spring (6). By 
boring or driving into the soil such subterranean 
streams may be tapped, the water then rises through 
the pipe, which may be regarded as an artificial fissure, 
this constitutes the artesian icell (c). 




Fig. 72. 
Equilibrium of liquids. 

The force that causes a rise of water through the fis- 
sure or pipe will be understood from the following 
simple observations. If a tube of glass open at both 
ends be inserted in a vessel of water, the liquid rises 
within the tube to the level at which it stands in the 
outer vessel.* 



* If the tube be of small caliber the water will rise to a level higher 
than that of the liquid in the vessel; this is due to the adhesion be- 
tween the glass and the water. Such adhesive force when operating 
in very small tubes is known as capillary aiiraction, the;term "capillary" 
being derived from the Latin capUhis, meaning a hair, and so applied 



SOURCES OF WATER. 



159 



The sketch (figure 72) represents a vessel commun- 
icatiug with a number of tubes of different sizes and 
shapes. If water be poured into such a vessel it will 
come to rest at the same level in each of the tubes. 
This fact warrants the oft-used expression, "Liquids 

vrill find their level." 
It is impossible to carry 
a liquid by its own 
pressure alone above 
the level of its source. 
By way of further 
illustration, prepare 
the apparatus sketched 
in figure 73. Provide 
a good -sized funnel, 
and attach to it a rub - 
ber tube. At the other 
end of the rubber in - 
sert a glass pipe. Hold 
the attached tube as 
shown in the figure 




Fig. 73. 



Liquid rising to the level of its source, ^nd pour water into 
the funnel : the liquid rises to the same height in the 
tube. Now lower the tube, so that the opening is 
below the water level in the funnel : the water now 
issues as from a fountain, and leaps nearly to the level 
of its source in the funnel. The friction of the flow- 



because the phenomenon manifests itself most strongly in small or 
hair-like tubes. It is by capillary attraction that a piece of bread ab- 
sorbs milk when dipped in the liquitl; that a sponge absorbs water ; 
that a towel dries our flesh. We know how efficient is an un-glazed 
towel over one in which the pores are closed by an impermeable gloss 



160 



DOMESTIC SCIENCE. 



iiig liquid against the tube, the resistance of the air 
through which it rises, and the force of the descending 
drops as they strike the rising stream, prevent the true 
level being fully reached. So in the case of the fissure 
spring or the artesian well : the tendency of the escap- 
ing stream is to throw itself to the level of its source 
in the surrounding hills. 




Fig. 74. 
Possible cause of intermittent springs. 

There are some springs that discharge water at cer- 
tain seasons only. These are known as mtermittent 
springs. It is believed that they are due to some such 
a formation as is shown in figure 74. During a wet 
season water would percolate through the soil and 
gather in the cavern, a ; as soon as it rose above the 
highest point in the exit passage, b, the water would 
flow to the opening and there appear as a spring. 
The flow would continue till the water sank below the 



SOURCES OF WATER. 



161 



entrance to the tube ; and then would cease till the 
cavern had again filled to the former level. This oper- 
ation is explained by the principle of the siphon, page 
31. The action may be well illustrated with the sim- 
ple apparatus here shown (figure 75). A glass vessel 

is provided with a 
bent delivery tube: 
if water be poured 
into the receptacle 
till the level of the 
liquid is above the 
Fig. 75. Vi* V. f • f f 

Apparatus to illustrate a possible cause of highest point 01 

intermittent springs. the tube, the water 

will run through the tube and the flow will continue 
till the liquid in the large vessel has sunk below the 
entrance to the pipe. 

Intermittent springs may be due to other conditions 
than the occurrence of such a cave. In a case similar 





Fig. 76. 
Intermittent springs. 

to that shown in figure 76, during high water season 
the level of the subterranean water may reach a, 
then a flow would occur at S : as the underground 
water level sank, however, the spring would cease. 
Potable water from springs is generally well adapted 



Ifi2 DOMESTIC SCIENCE. 

for domestic purposes ; the chief cause of objection 
to its use being its hardness. Water from fissure 
springs and artesian wells is generally free from sur- 
face filth, the subterranean supply being deeply set. 
Good spring water is generally clear and well aerated. 

The water of rivers usually contains much mineral 
matter, and is, in consequence, hard ; it is seldom free 
from organic impurity. This contamination is the 
direct consequence of the drainage exercised by rivers 
upon the land through which they flow. Large quan- 
tities of organic filth reach the rivers from manured 
soils ; and in marshy districts the running waters are 
frequently dark from the peaty matters dissolved from 
the ground. In the case of large rivers with towns 
and cities upon their banks, vast quantities of sew- 
age are discharged into the streams, rendering 
the water entirely unfit for drinking or culinary pur- 
poses. 

It is true, certain processes of natural purification 
are in continual operation, and these greatly mitigate 
the contaminating effects above referred to. The at- 
mospheric oxygen, which freely dissolves in water, 
unites with the products of organic decay there present, 
and thus renders them in time comparatively inert. 
Running water tends, therefore, to purify itself, but 
the completeness with which this will be accomplished 
depends upon the amount and the nature of the dis- 
solved matters, and the proportion of free oxygen 
present. The extent of this self -purification process 
is a matter of considerable uncertainty. Some chem- 
ists have asserted that a sewage -laden stream will free 
itself from all impurity in flowing but a few miles, and 



SOURCES OF WATER. 163 

others have as strongly denied the possibility of such a 
thing-.* 

■ In country towns, running streams, which have al- 
ready received attention, and wells, which are now to be 
considered, are the only common sources of sup- 
ply. Surface or shallow wells are usually made by dig - 
ing or boring into the earth till an impermeable layer is 
reached. Upon this the subterranean water rests, and 
the well merely taps the supply. At such slight depths 
the pressure .is insufficient to cause the water to rise of 
itself as from a deep artesian pipe. The most of such 
wells, when new, yield fairly good water, hard or soft 
according to the depth of the shaft and the nature of 
the surrounding soil, but after a short time the wells 
become contaminated through surface drainage. Upon 
the nature of this contamination we shall yet have oc- 
casion to speak farther. It is evident that the dangers 
of pollution are greatly diminished in the case of deep 
wells ; the streams that supply these being purified by 
their percolation through the soil. All surface wells 
should be frequently cleansed. The openings should be 
properly protected by curbs and covers, against the 
accidental entrance of foreign bodies. The best of 
wells may be fouled through negligence. 



* In one of the reports of the English Commissioners on River Pol- 
lution, it is declared that "the oxidation of the organic matter in sew- 
age proceeds with extreme slowness, even when the sewage is mixed 
with a large volume of unpolluted water ; and that it is impossible to 
say how far such water must flow before the sewage matter becomes 
thoroughly oxidized. It will be safe to infer, however, * * * that 
there is no river in the United Kingdom long enough to effect the de- 
struction of sewage by oxidation." 



164 DOMESTIC SCIENCE. 



CHAPTER 18. 

WATER, A SOLVENT FOR SOLIDS ; HARDNESS OF WATER. 

WATER has been called "Nature's universal sol- 
vent," and this appelation is justified by the fact 
that there are few if any substances that can be kept 
in contact with water without yielding something to its 
dissolving action. In undergoing solution in water, 
the particles of a solid body become so separated that 
the water is uniformly diffused among them. In a 
solution, the solid particles are so finely divided and so 
thoroughly incorporated with the liquid that the highest 
powers of the microscope fail to reveal them. The 
liquid may be filtered, but the dissolved solid passes 
through with the menstruum; and in all physical re- 
spects the liquid and solid appear as a single sub- 
stance. 

The solvent power of water toward different solids 
is of varying intensity. Thus, a given quantity of 
water will at ordinary temperatures dissolve five times 
as much sugar as it will alum. When water has dis- 
solved of any solid the full amount that it is capable 
of dissolving, the liquid is said to be saturated, and 
the energy of the dissolving action decreases as the 
saturation point is approached. In domestic opera- 
tions the solvent power of water is of very great ser- 
vice. Through it we make our pickling brines, and 
prepare sweetened and flavored dishes in great variety ; 



WATER, A SOLVENT FOR SOLIDS. 165 

but for it we could not successfully scrub a floor, or 
even wash our hands. 

The power of water to dissolve solids is greatly in- 
fluenced by changes of temperature ; as a rule heat in- 
creases the energy of solution, though to this there are 
exceptions ; thus, hot water will dissolve many times 
more sugar than will cold water ; yet ice water will 
dissolve twice as much lime as will water at a boiling 
temperature. In attempting the solution of any solid, 
the substance should be pulverized as finely as pos- 
sible, as by such means much greater surface is exposed 
to the action of the liquid. This may be illustrated by 
simple means. In an experiment, the writer took a 
lump of rock salt, an equal weight of ordinary table 
salt, and the same amount of fine sifted salt. Each of 
these was placed in a vessel by itself ; then an equal 
quantity of water was added to each ; at intervals the 
vessels were shaken, all being subjected as nearly as 
possible to the same degree of agitation. The sifted 
salt was completely dissolved in twenty minutes ; the 
table salt had disappeared in forty -three minutes, by 
which time the size of the lump had scarcely dimin- 
ished ; and after five hours part of the rock salt was 
still undissolved. 

The solution of a solid may be much hastened by 
frequently agitating the mixture, either by shaking or 
stirring. If the liquid be kept at rest, those portions 
that immediately surround the solid substance become 
saturated, and being thus increased in density they 
tend to remain at the bottom, so that mixture can take 
place only by the slow process of diffusion ; and the 
unsaturated liquid above is kept away from the solid 



166 DOMESTIC SCIENCE. 

body. In an experiment to illustrate this, the author 
took two equal quantities of alum. These were placed 
in separate flasks, and to each the same quantity of 
water was added. The contents of one flask were 
shaken at intervals ; the other was allowed to remain 
still. In the first vessel the solid was entirely dissolved 
in three-quarters of an hour, while in the second, part 
of the alum still remained "solid after twenty -two days. 

In preparing any aqueous solution in large quantity 
it is well to place the finely divided solid in a basket or 
a bag of coarse material, and suspend this in the upper 
part of the liquid. As the water in contact with the 
solid becomes saturated, its specific gravity is increased, 
and in consequence it sinks, thus giving place to other 
liquid particles. As an illustration of the efficiency of 
this method the following results of experiment are in- 
structive. A weighed quantity of salt was placed in 
an open vessel, and a measured amount of water was 
poured upon it. An equal quantity of salt was sus- 
pended in a cage of wire gauze, just beneath the sur- 
face of a like measure of water in another vessel. In 
the first, a quantity of solid remained undissolved after 
three weeks ; in the second, all the solid had disap- 
peared from view in forty -seven minutes. 

In consequence of the great solvent energy of water, 
it is impossible to find as a natural occurrence a speci- 
men of pure water. 

It will be profitable to consider briefly the amount 
and kind of the solid matters in natural waters. The 
following table shows the amount Ox total solid matter 
in certain specimens of water, expressed in grains of 
solids per gallon of water : 



WATER, A SOLVENT FOR SOLIDS. 



1G7 



Source, 



Total solids 

expressed in 

grains per gallon. 



Authority. 

• Wells. 
Johnston. 
Wanklyn. 
Johnston. 
Johnston. 



River Loka, Sweden - - 0.05 

Boston, U. S., water works - 1.22 

Loch Katrine, Scotland - 2.3 

Schuylkill River at Philadelphia 4.26 

Detroit River, Michigan - 5.72 

Ohio River at Cincinnati - 6.74 " 

Loire at Orleans - - - 9.38 " 

Danube, near Vienna - - 9.87 " 

Lake of Geneva - - - - 10.64 

River Rhine at Basel - - 11.8 Wanklyn. 

Thames at London - - 18.5 " 

Average of 12 artesian wells, 

Provo, Utah - - '- 18.6 The Author. 

Salt Lake City supply - - 16.92 

Spring water, Provo, Utah - 23.3 " 

Formation Springs, Idaho - 27.8 " 

Octagon Spring, at Soda 

Springs, Idaho - - 126.66 " 

Well water, Gunnison, Utah - 148.01 " 

" Ninety per cent. Spring," at Soda 

Springs, Idaho - - 198.41 " 

Warm Springs, Spanish Fork 

Canyon, Utah - - 413.72 

Atlantic Ocean - - 2,688.00 Wanklyn. 

*Salt Lake - - 11,777.64 The Author. 

fDeadSea - - - 17,064.42 

The amounts of solid material as expressed above 
may seem very great, but the actual percentage is 

* The water of the Great Salt Lake is subject to great fluctuations as 
regards its contents of solid matter, owing to the variations in amount 
of supply and in the rate of evaporation. In 1849 the lake water, ac- 
cording to Dr. Gale, contained 22.282 per cent, of solids ; that time, 
however, was one of phenomenally low water, and consequently of 
great concentration. In December, 1885, the author found the water 
to contain 16.7162 per cent, solids, and in August, 1889, it held 19.5576 
per cent. The mean of these two analyses shows 18.1369 per cent., or 
11,777.64 grains of solid matter per gallon. 

t Great discrepancy exists among published accounts of the solid 
contents of Dead Sea water. Bernan gives 14,025.48 grains per gallon ; 
Captain Lynch collected a sample at a depth of lllO feet, and found it 
to contain 18,902 grains per gallon. The amount given above (17,064 
grains per gallon) was determined by the author in a sample taken 
from the Dead Sea in April, 1886, by Dr. J. M. Tanner, of Logan, Utah. 



11)8 DOMESTIC SCIENCE. 

small ; 10 grains of solids to the gallon represents only 
.0145 of 1 per cent, by weight. 

The presence of mineral matter in water may impart 
to the liquid the property of hardness, which may be 
concisely defined as the power of curdling soap with- 
out the formation of a lather. The minerals most ef- 
fectual in causing hardness are compounds of calcium 
and magnesium. Salts of these unite with the fatty 
acids* of the soap, forming insoluble curdy compounds, 
and all the lime and magnesium in the water must be 
so combined before a lather can be produced. A large 
amount of soap is therefore lost so far as any cleansing 
effect is concerned. 

The hardness of water is usually reckoned in terms 
of this soap destroying power. It has been adopted as 
a rule among chemists, to consider the soap destroying 
effect produced by 1 grain of calcium carbonate in a 
gallon of water as one degree (1°). A water of 10° 
hardness would contain therefore 10 grains calcium 
carbonate per gallon, or the equivalent of this in other 
soap destroying compounds. 

Lime carbonate is but slightly soluble in pure water, 
but dissolves readily in water containing carbon di- 
oxide ; this gas is present in most natural waters. By 
boiling water so charged, the carbon dioxide is expelled, 
and the lime carbonate being so slightly soluble in the 

* In a chemical sense, soap is to be regarded as a compound of cer- 
tain alkalies with the acids of fats. The fatty acid in common soap is 
oleic acid ; and ordinary hard soap is chiefly sodium oleate ; soft soap 
is potassium oleate. In contact with hard waters the soap loses its 
sodium or potassium, these substances being replaced by calcium and 
magnesium ; thus, oleates of calcium and magnesium are produced, 
which are still soaps, though they are nisoluble in water, and therefore 
valueless for hithering purposes. (See chapter 36, Part IV.) 



WATER, A SOLVENT FOR SOLIDS. 



169 



water after boiling, falls as a solid precipitate. Look 
inside a much -used tea kettle; there will be found a 
heavy deposit of lime salts, as thick scale or incrusta- 
tion. It is plain from this that by boiling water con- 
taining calcium carbonate in solution, the hardness of 
the liquid may be materially diminished. Hardness 
that is removable by boiling is called temporary hard- 
ness. Other compounds of calcium, such as the sul- 
phate (gypsum) and the chloride, as also the com- 
pounds of magnesium, impart to the water permanent 
hardness, which is not removed by simply boiling the 
liquid, because the hardening solids are not thereby 
precipitated from solution. 

For general household purposes, soft waters are the 
best, though for many operations a considerable de- 
gree of hardness may be tolerated. The following 
table expresses the hardness of several natural waters : 

Degrees of hardness. 



Source. Total. 


Perman 


- Tem- 


Authority. 




ent. 


porary. 




London Thames - 10.5 


— 


— 


Wanklyu. 


Klrby Shore, Westmoreland 25. 


— 


— 


" 


Hillside Spring, Provo.Utah 17. 


5 


12 


The Authoi 


Well water, Gunnison, Utah 6.5 


1.7 


4.8 


" 


Average, 9 artesian wells. 








Provo, Utah - - 15.2 


5.4 


9.8 


" 


Average, 11 artesian wells, 








Salt Lake City - i^.l 


lU.T 


7.4 


li 


Salt Lake City supply - 13.4 


6.9 


6.5 


" 



It is to be remembered that the hardness of water de- 
pends largely upon the kind as well as upon the amount 
of solid matter present. The water from Gunnison, 
Utah, is named in the table on page 167 as containing 
148.01 grains of solid matter to the gallon ; yet this is 
a relatively soft water, as is seen from the table on 

7 



170 DOMESTIC SCIENCE. 

page 169^ which shows for it a total hardness of but 
6.5°, and of this 4.8° may be removed by boiling, 
leaving a permanent hardness of but 1.7°. The 
solid contents of this water, however, are mostly 
compounds of the alkalies. The water here referred to 
is remarkable in many w^ays ; its specific gravity is 
high, and though it is constantly used as a potable water, 
its taste is tolerable only to those who have become ac- 
customed to it. 

The continued use of water that is highly impreg- 
nated with salts of lime and magnesia is supposed to 
be a cause of goitre or hig neck. This disorder is an 
enlargement of the thyroid gland in the neck.* From 
its prevalence in the limestone regions of Derbyshire, 
England, it is popularly called "Derbyshire neck." 
Most recent investigations lead to the belief that the 
potency of hard waters in producing this disorder has 
been over estimated. Contaminated water may favor 
the disease, but that the use of such water is the sole 
cause can scarcely be credited in the light of demon- 
strated facts. 

* Johnston reported that in a jail at Durham, England, all the pris- 
oners suffered from neck swelling. An examination of the water there 
used showed that it contained 77 grains of solids per gallon, mostly 
compounds of magnesia and lime. The use of the water was then dis- 
continued, a purer kind being substituted, containing but 18 grains of 
solid matter per gallon. The goitrous disorder immediately sub- 
sided. 



WATER, A SOLVENT FOR GASES. 171 



CHAPTER 19. 

WATER, A SOLVENT FOR GASES. 

''PHE solvent power of water is not confined to its 
1 action on solids ; gases also may be dissolved in 
large quantities. The commonest gaseous admixtures 
in ordinary waters are the constituents of air. Much 
good results from such solution of air in water ; upon 
the atmospheric gases so held, fishes and other aquatic 
animals depend for respiration. It is a popular mis- 
take that only land -animals breathe air: without this 
medium of respiration the tiniest creature of the sea 
would die. A living fish placed in non- aerated water 
quickly expires ; and the same result follows * if the 
fish be kept in an inadequate amount of water, with- 
out renewal ; the fish then dies from suffocation caused 
by its own respiratory products, just as a man shut in 
a closed room from which the gaseous emanations of 
his body cannot escape will be poisoned by his own 
breath. A strong example of our subject is found in 
the growth of the tiny coral animals. These belong 
to the polyp family, and are very small and simple in 
bodily structure. They possess the power of extract- 
ing the calcareous matter from the sea water, and of 
forming from the same a hard, external skeleton, 
analogous in composition and use to the shells of 
mollusks, such as oysters and snails. Corals usually 
congregate in great numbers, the accumulations of 
their external skeletons forming coral reefs. Such reefs 



172 DOMESTIC SCIENCE. 

are found only in places that are freely exposed to the 
action of the waves : the little polyps seem to delight 
in the breaking of the surf, and the whirl of agitated 
waters. Farther, — they are never found living at a 
great depth ; a hundred feet seems to be their limit. 
These peculiarities seem to be due to the animals' 
need for air. In still water or at a great depth the 
coral polyps would be deprived of air, in consequence 
of which they could not survive ; but the agitation of 
the surface water entangles air sufficient for their use. 

It is remarkable that the atmospheric gases do not 
dissolve in the proportion in which they exist in the 
air. In pure air there will be found about 20.9 per 
cent, of oxygen and 79.1 per cent, of nitrogen; the 
other constituents need not be considered in this con - 
uection (see Chapter 3). Water that has been fully 
aerated, however, contains the atmospheric gases in 
the proportion of 32 per cent, oxygen and 68 per cent, 
nitrogen. This increased amount of oxygen is of 
great benefit to aquatic animals, the nitrogen, in res- 
piration serving merely as a dilutent. * 

To drinking water, the dissolved air imparts a pleas- 
ing and somewhat pungent taste. This fact may be 
realized by anyone who, for contrast, will drink for a 
time water from which the air has been expelled b}' 
boiling. 

Inasmuch as heating water serves to expel its dis- 



* It has been discovered by Dr. Hayes, "that the water of the ocean 
contains more oxygen near its surface than at a depth of one or two 
hundred feet. This fact has probably some connection with the com- 
parative scarcity of animal life at great depths. When water is in 
contact with an atmosphere of mixed gases, it dissolves of each a 
(luantity precisely equal to that which it would have dissolved if in 
contact with an atmosphere of this gas alone." Wells. 



WATER, A SOLVENT FOR GASES. 173 

solved gases, it is plain that a rise of temperature will 
diminish the solvent power of the liquid for gases ; 
this view is substantiated by following facts : Experi- 
ment has shown that water at 78° C is able to hold 
in solution 586 times its own volume of dried ammonia 
gas; at 59° C. the water can hold 727 volumes; and 
at 32° C. it may contain 1050 volumes of the gas. A 
solution of ammonia gas in water is sold as aqua 
ammonia, or tvater ammonia (the common hartshorn 
of the shops). By warming such, large volumes of 
the gas will be given off. 

The ill -smelling gas, hydrogen -sulphide, is soluble 
in water; indeed the waters of so-called sulphur 
springs are usually natural solutions of hydrogen 
sulphide. The influence of temperature upon the 
solvent power of water for this gas, is illustrated by the 
followingfacts : At 78°C. one volume of water dissolves 
2.66 v^olumes of hydrogen sulphide ; at 59° C. water 
dissolves 3.23 times its own volume of the gas : at 32° 
C. it may hold 4.37 volumes. 

Another gaseous substance commonly found in 
natural waters is carbon dioxide. At 14° C. water 
can hold in solution its own volume of this gas : 
at 0° C. it may contain 1.8 volumes. 

The pressure to which liquids are subjected greatly 
affects their power of solution for gases. Thus in the 
case of carbon dioxide, under a pressure of one atmos- 
phere (15 lbs. to the square inch), at 14° C. water 
dissolves its own volume of the gas ; under a pressure 
of two atmospheres, (30 lbs. to the square inch) the 
temperature being unchanged, two volumes may be 
absorbed, and so on ; within certain limits the solvent 



174 DOMESTIC SCIENCE. 

power is directly proportional to the pressure. An 
aqueous solution of carbon dioxide constitutes the 
common soda water. By the action of some mineral 
acid (usually sulphuric acid) on sodium bicarbonate, 
chalk or marble dust, carbon dioxide is generated in 
great quantity ; the gas is conducted into a stout closed 
vessel containing water ; as the gas accumulates, the 
pressure increases ; and at the same time the water 
being kept violently agitated, the gas passes into 
solution. It will be held captive by the water, how- 
ever, only as long as the pressure continues ; as soon 
as the liquid is drawn from the holder the gas escapes 
giving the effervescent and pungent qualities which are 
sought. * 

The fact of the readiness with which gases dissolve 
in water, should restrain us from using for drink- 
ing purposes, water that has stood long in open vessels. 
Water that has been exposed, even for an hour or 
two, to the air of a closed room, will be found to be 
charged with the gases of the apartment ; and these 
may be of the most deleterious kind. In the treatment 

* The question of the wholesomeness of soda water has excited some 
general interest. The presence of small quantities of carbonated 
water in the stomach seems to produce pleasing and exhilarating 
effects ; and if the preparation be pure, it is difficult to see what harm 
is likely to result from its moderate use. Some soda-water makers, are 
not careful to use pure water; and are indifferent to the cleanliness of 
their apparatus. It is possible too, that metallic compounds may re- 
sult from combinations with the material of the holders and pipes. 
The admixture of flavoring syrups is objectionable, for the reason that 
the purity of such preparations cannot be relied on, and the coloring 
matters used to impart the deceptive tints to strawberry, raspberry, 
blackberry and other syrups are frequently of a deleterious kind; and 
farther, the habitual taking into the system of large quantities of sac- 
charine material is certainly injurious to health. 



WATER, A SOLVENT FOR GASES. 175 

of the sick, precautions are necessary that the patients 
drink not of any liquid that has been long exposed to 
the air of the room. 



176 DOMESTIC SCIENCE. 



CHAPTER 20. 

ORGANIC IMPURITIES IN WATER. 

THE impurities most to be feared in water that is 
used for domestic purposes are of an organic nature, 
— that is, they are products of vegetable and animal 
decay.. An average amount of mineral impurities need 
not render water at all unlit for use. A water contain- 
ing less than 15 grains of calcium salts to the gallon is 
usually considered good ; and 20 grains of such solids 
to the gallon is not an unusual amount; indeed, 
waters containing even three times the last named 
quantity of calcium carbonate have been drunk for long 
periods without producing any marked deleterious 
effect, though such waters are apt to be hard ; and hard 
waters are poorly adapted for laundry and cooking 
purposes. But a very small amount of organic impurity 
may render the water unsafe for drinking purposes. 

Organic matters containing nitrogen are most 
deleterious. It is common with chemists to determine 
this organic impurity in the form of ammonia, it being 
possible to convert all such nitrogenous matters into 
ammonia, and to determine the amount present with 
accuracy. The ammonia present in waters as a result 
of decay that has already taken place is determined as 
free ammonia ; the rest of the nitrogenous organic 
matter may be decomposed, and converted into 
ammonia by the analytical process ; this is called 
albuminoid ammonia. Regarding the amounts of these 



ORGANIC IMPURITIES IN WATER. 177 

matters allowable in drinking water according to the 
established standard of safety, Mr. Wanklyn of Eng- 
land, agenerally recognized authority upon this subject, 
has said: "I should be inclined to regard with some 
suspicion a water yielding a considerable quantity of 
free ammonia, along with 0.05 parts of albuminoid 
ammonia per million.* * * Albuminoid ammonia above 
0.10 per million begins to be a very suspicious sign, 
and over 0.15 oughtto condemn a water absolutely." 
Below are exhibited the results of some analyses of 
natural waters. 

Parts per million. 



S^^i'^e- anfmonia 


Ahluminoid ... .^ 
. ammonia, ^"thority. 


Town water, Manchester, 








England . . ' . 


.01 


.06 


J. A. Wanklyn. 


Glasgow, Scotland, Loch 








Katrine 


.00 


.08 


<( 


London Thames, at high 








tide 


1.02 


.59 


(( 


Average 10 artesian wells, 








Provo City, Utah 


•2.n 


.18 


The Author. 


Average IG surface wells, 








Provo City, Utah 


.125 


.284 


" 


In-doors pump, Provo 








City, Utah 


0.73 


5.40 


<( 


Artesian well, Spanish 








Fork, Utah 


.72 


5.18 


<( 


Average 13 artesian wells. 








Salt Lake City, Utah . 


.669 


.22 


<' 


Surface well,Salt Lake City 


3.28 


.34 


« 


City water mains, Salt 








Lake City 


.13 


.052 


<< 


Emigration canyon stream. 








Salt Lake valley 


.046 


.045 


J. T. Kingsbury. 


Red Butte canyon stream 


.023 


.120 


" 


Parley's canyon stream . 


.010 


.060 


" 



Associated with organic impurity of the kind describ- 
ed, water may contain large quantities of chlorine, 
usually combined with sodium as common salt, or with 



178 DOMESTIC SCIENCE. 

calcium as calcium chloride. This may result from the 
presence of sewage filth or drainage from cess pools ; 
though the discovery of chlorine in water, unaccom- 
panied by organic impurity, is not of such serious 
import. 

The following table will convey an idea of the vary- 
ing amounts of chlorine in different waters. 



Source. 


Chlorine. 
Grains per gallon. 


Authority. 


Bala Lake, Wales . 


0.7 


Wanklyn. 


Thames at London 


1.2 




" 


Average 22 surface wells, 








Provo City, Utah 


1.22 


The 


Author 


Average 8 artesian wells, 








Provo City, Utah 


2.029 




" 


Average 8 artesian wells, 








Salt Lake City, Utah , 


3.688 




(< 


Surface spring, Provo City 


.977 




<< 


Artesian well, Spanish 








Fork, Utah 


.992 




" 


Salt Lake City supply 

TIT . „£ 


.87 

11 J._ _!! 




fC 



The pres.ence of small amounts of organic matter 
would not of itself prove a source of injury to health. 
The danger lies in the fact that living organisms flourish 
in water so contaminated, and these may be of an 
injurious type since man)^ forms of contagious disease 
have been proved to be always associated with the ex- 
istence of such organisms within the system. The 
germs of cholera, small pox, and many forms of fevers, 
thrive in water that is organically impure. Dr. Cyrus 
Edson, the well known sanitary chemist of New York, 
has declared his belief that ninety -nine per cent, of 
cholera cases are propagated through the medium of 
drinking water. The reports of the sanitary officials 
in India show a close relationship between the epidemic 
outburst of cholera, to which that country has been 



ORGANIC IMPURITIES IN WATER. 179 

frequently subject, and the use of polluted drinking- 
water. Enteric or typhoid fever is more frequently 
spread by the use of contaminated water than in any 
other way. * 

Dysenteric and diarrhceal affections are in many cases 
directly traceable to polluted water. The sample 
named "In -doors pump, Provo City, Utah," in table on 
page 177, was taken from a well, provided with a curb 
and a drainage pipe. The water was used in a large 
boarding house, and the fact was reported that severe 
dysentery was common among the inmates. An ex- 
amination of the well was made, and the drain pipe 
was found to be completely choked, so that the foul 
wastes made their way back to the well, and this repuls- 
ive mixture was drunk. The pipe was cleared, the well 
thoroughly cleansed, and the derangements in the health 
of the inmates straightway disappeared. 

Mr. Wanklyn, the English analyst, examined water 
from a well at the Leek Workhouse ; and found it to 
contain .02 parts of free ammonia, and .34 parts of 
albuminoid ammonia per million of water. Of this 
occurrence he says, ''In the Leek Workhouse there hajS 
been for years past a general tendency to diarrhoea, 
which could not be accounted for until the water was 
examined and shown to be loaded with vegetable 



* In referring to typhoid fever as a result of the use of water con- 
taminated with filth, Drs, Huxley and Youmans say: "The instances, 
of its originating in this way are too numerous, and have been too 
clearly traced to admit of a doubt of the fact ; nor does mere dilution 
of the poison remove the danger as the following will show: A recent 
outbreak in an English town was traced to the milk with which 
numerous families were served, and it was conclusivly proved that the 
milk was poisoned by being stored in cans that had been washed with 
water contaminated with sewage from an imperfect drain." 



180 



DOMESTIC SCIENCE, 



matter." He adds, "A well on Biddulph Moor, a 
few miles from Leek, yielded .05 grain chlorine per 
gallon, and .03 free, and .14 albuminoid ammonia per 
million. The persons who were in the habit of drink- 
ing this water suffered from diarrhoea."* 




Fig. 77. 
Suspended matters in well-waters. 

Well waters are often contaminated by the entrance 
of foreign matters because the openings are not suffi- 
ciently protected. The author has examined many 



* "Dissolved or suspended organic matter, whether of vegetable or 
animal origin, will cause diarrhoea. In the recent war great numbers 
of cases occurred from the use of marsh or ditch water; the sickness 
ceased when wells were sunk." 

"Mineral matters, either dissolved or suspended, will give rise to it if 
present in considerable quantity." 

"WaterMmpregnated with nitrate of lime will produce diarrhoea. 
]}rackish water acts in the same way." 

Hl'XLEY & YOUMANS. 



ORGANIC IMPURITIES IN WATER. 



181 



specimens of water from wells so exposed, and is con- 
vinced that reckless carelessness exists as to protecting 
the wells from dust, and the like. Nearly one -third 
of the waters so examined have been found to contain 
suspended particles, which, under the microscope, reveal 
themselves (figure 77) as partly -decayed fibres of 
straw ; cotton ; wool (c) ; hair (e) ; pollen grains 




Fig. 78. 
Living organisms iu potable waters. 

from plants (6) ; spores of fungi ; scales of butterflies 
and moths (a). Dr. Parkes, of London, referring to 
the results of his examinations of water in that great 
city says, "Fibres of cotton, wool or linen, starch 
cells, (figure 77,/) macerated paper, human hairs, yel- 
low globular masses, and striped muscular fibre (un- 
digested meat) (d), with squamous epithelium cells, 
are all indicative of contamination of the water with 



182 DOMESTIC SCIENCE. 

human refuse, and most probably with sewage. 
Amongst these matters and feeding on them will 
probably be found living organisms of low types, such 
as bacteria (micrococci, bacilli, and vibriones) amoebae 
and infusoria. These organisms are not in themselves 
dangerous, but they indicate the presence of matters, 
chiefly organic, upon which they feed, and amongst 
them may be those germ-producing organisms which 
so often find their way into sewage." 

The accompaning sketch (figure 78) shows a few of 
the living organisms reported as having been found in 
potable waters ; a, represents a species of green mold 
(penecillium) ; 6, another form of mold (mucor) ; d, 
a fungus (aspergillus) ; e, forms of bacteria (micro- 
coccus, bacillus, and vibrio) ; c, a simple form of 
animal belonging to the protozoans (vorticella) ; 7, 
another protozoan, (paramecium). 



SIMPLE TESTS FOR WATER. 183 



CHAPTER 21. 

SIMPLE TESTS FOR PURITY IN POTABLE WATER. 

IN CASES of suspected water contamination, a sam- 
ple should be submitted to a competent chemist for 
analysis. He will certify to the state of purity in the 
sample, and as to the possibility for bettering the water 
by any simple means. From him the following items 
of information should be asked : 

1. The total amount of solid matters present. 

2. The nature of the dissolved solids. If possible a 
full analysis of the solids should be made, and in all 
cases the predominating metals should be determined, 
and the nature of the prevailing salts, whether carbon - 
ates, sulphates, or chlorides. 

3. The degrees of hardness, expressed as total hard- 
ness, temporary hardness and permanent hardness. 

4. The amount of chlorine present. 

5. The amount of nitrogenous organic matter de- 
termined as free ammonia and albuminoid ammonia. 

6. The presence or absence of deleterious gases. 

7. The presence or absence of poisonous metals. 

8. The nature of the mechanically suspended 
matters. 

From such facts, the general condition of the water 
can be inferred. However, it is not always possible to 
secure the aid of chemical skill in examining drinking 
water ; it is proper therefore that we become acquainted 
with at least a few of the t^eterminative tests to which 



184 DOMESTIC SCIENCE. 

water can be subjected. The following observations may 
be made by any one with practice and scrupulous care, 
and by such assistance much reliable information as to 
the purity of any water may be gained. 

1 . Color. It is a common statement that pure water 
is colorless ; this, however, is strictly true of small 
bodies of water only ; for when viewed through great 
depths, the purest of waters possesses a distinctly bluish 
tint. To determine the color of a potable water, fill 
with the sample a tall cylinder or bottle of clear white 
glass ; cylinders made for the purpose, about two feet 
in length are best adapted. Place the vessel on a white 
dish, or a sheet of white paper, and carefully examine, 
looking from the surface downward. Good waters will 
show the bluish tint above referred to ; any large amount 
of vegetable impurity will give a greenish color ; and 
sewage filth will tint the water yellow or light brown. 
If salts of iron are present in the water, the last 
named indication will be unreliable, as such salts 
themselves would give to the water a brownish hue. 

2. Clearness. Examine as for color ; also hold the 
vessel containing the sample toward the light ; then 
view it when held before some black object. Any tur- 
bidity is an indication of the presence of organic im- 
purities in solution, or of suspended solid matters. All 
turbidity is a sign of contamination, though the op- 
posite must not be inferred — that clear water is neces- 
sarily pure. There is a wide -spread popular error 
on this point, and it has led to the use of very foul 
waters because of their sparkling appearance. One of 
the clearest waters ever examined by the author, was 
taken from a pump in Greenwood Cemetery, Brooklyn. 



SIMPLE TESTS FOR WATER. 185 

N. Y. ,* yet it wasfound to be heavily laden with nitrates, 
which, doubtlessly, were.derived from the bodies there 

entombed, t 

3. The odor of drinking water is an important char- 
acteristic. To determine it, procure a quart bottle ; 
see that it is clean and provided with a well -fitting 
cork. Half fill the bottle with the water under ex- 
amination ; cork the vessel and set it aside in a warm 
place for a few hours ; then shake it well, open and 
smell. Any perceptible odor should condemn the 
water for domestic use until a determinative analysis 
has been made. If no odor is perceptible after gentle 
warming, the water should be heated nearly to boiling, 

* A number of pumps are to be found in that wonderful and beauti- 
ful city of the dead, and I have looked with horror upon visitors drink- 
ing from these grave-fed wells. Such water is highly charged with 
the nitrates and nitrites of decomposing flesh, and water so impreg- 
nated has a cooling, saline taste, very pleasant to the palate of the 
blissfully ignorant drinker, and sure to excite subsequent thirst, 
which will lead to continued draughts. During another visit to Green- 
wood in the summer of 1889, I was glad to see that a notice had been 
placed over each of the pumps, stating that the water was to be used 
for irrigating the flower beds only: but the pumps are still there, with 
the levers free, and visitors continue to drink at them. Should we 
marvel that the silent metropolis is so well tenanted ? 

t The London Lancet in referring to water so contaminated, says : 
" It is a well ascertained fact, that the surest carrier and the most 
deadly fruitful nidus of zymotic contagion, is this brilliant, enticing- 
looking water, charged with the nitrates which result from decompo- 
sition." 

Johnston says of such waters: " The water of a well close to the old 
churchyard on the top of Highgate Hill was examined by the late Mr. 
Noad, and found to contain as much as 100 grains of solid matter to 
the gallon, 57 grains of which consisted of the nitrates of lime and 
magnesia. This large amount of nitrates is traced to the neighboring 
graveyard, as such compounds are generally produced where animal 
matters decay in porous soils. . . . While the buried bodies were 
more recent, animal matters of a more disagreeable kind would proba- 
bly have been found in the well, as I have myself found them in tlie 
water of wells situated in the neighborhood of farm-yards." 



186 DOMESTIC SCIENCE. 

the odor being tested at frequent intervals as the heat- 
ing proceeds. Remember that pure water is odorless. 

4. Taste. Water intended for household use should 
be entirely devoid of taste. Any perceptible flavor 
should be considered as strong evidence that the 
liquid is contaminated, and chemical tests should be 
employed. As many mineral ingredients impart but a 
feeble taste to water, these tests must be made with 
critical care. Many waters that seem tasteless while 
cold develop a positive taste if gently warmed. Do not 
consider the flat insipid nature which all ordinary water 
acquires by boiling, as a proof of contamination. 

5. The presence or absence of chloriiie should be next 
determined. This can be satisfactorily done by a com- 
petent chemist only, though the method of proceeding 
is simple. A drop of pure nitric acid and a few drops 
of clear silver nitrate solution are to be added to the 
water under test. A milkness or turbidity is due to 
the formation of silver chloride, and is a proof of the 
presence of chlorine in the sample. As was stated on 
page 178, the presence of chlorine in moderate quantity 
is a sign of danger only when associated with organic 
matter. 

6. The presence of organic matter in water is difli- 
cult to determine, except by complicated chemical tests. 
Yet such determination is of utmost importance in de- 
ciding uponthe wholesomeness of water. Much infor- 
mation upon this point, however, may be gained from 
the tests on color, odor and taste as before described. 
Heisch's test for organic impurity in water may be 
made as follows : "Fill a clean pint bottle three -fourths 
full of water; dissolve a teaspoonful of loaf or granu- 



SIMPLE TESTS FOR WATER. 187 

lated sugar ; cork the bottle and set it in a warm place 
for two days. If the water becomes cloudy or muddy 
it is unfit for domestic use. If it remain perfectly 
clear it is pro6a5/// safe to use." Some waters con- 
tain so much organic filth that when boiled the pollut- 
ing substances coagulate, as does the white of an egg 
when heated ; when the water cools the impurities 
separate in flocks. 



188 DOMESTIC SCIENCE. 



CHAPTER 22. 

PURIFICATION OF WATER. 

THE fact that water becomes so readily contaminat- 
ed with both organic and inorganic impurities, 
gives great importance to the subject of water purifi- 
cation. Many methods of improving the qualities by 
simple treatment have been proposed and practiced. 

For operating on a small scale as for domestic 
purposes, boiling has long been in favor. This treat- 
ment may produce important changes in potable water. 
For example, consider a specimen of water possessing 
great temporary hardness, and moderately contaminat- 
ed with organic refuse. As the boiling proceeds, the 
dissolved gases of the water, among them the carbon 
dioxide, which is sure to be present in such a sample, 
will be expelled ; the lime carbonate, from which the 
water derived its quality of temporary hardress will 
separate from solution, and fall as a sediment, leaving 
the water comparatively soft. This is the easiest and 
the cheapest known method of softening on a small 
scale such lime -carbonate waters. 

Another probable result of the boiling will be the 
coagulation and consequent separation of certain forms 
of organic matter. Farther than this, the boiling 
temperature will kill many if not all of the living germs 
present in water, thus insuring the liquid against 
the power of communicating specific diseases. Mudai 
discussion has arisen among scientists as to the minimuio 
temperature that is fatal to the common forms, of 



PURIFICATION OF WATER. 189 

bacterial life, and from the facts adduced by the con- 
troversy we may conclude that the temperature of 212° 
F. will effectually destroy all living organisms found 
in water, except possibly the spores of certain bacteria, 
and these may be surely killed by boiling the water 
several times at intervals, allowing time between the 
boilings for the spores to develop. Parkes declares 
his belief that there is scarcely any doubt that the 
specific poisons of cholera, enteric fever, and other 
forms of contagion such as are commonly propagated 
through the medium of impure drinking ^ater, are 
destroyed with certainty by even afew minutes' boiling. 
It must be remembered however, that at great altitudes 
water boils at a temperature considerably below 212° 
F. Under such conditions of diminished heat, the 
certainty of destroying microscopic organisms by boil- 
ing the water is considerably lessened. 

Boiled water possesses an insipidity which, to many 
people, is almost nauseating ; this taste is due to the 
non- aerated condition of the water, the atmospheric 
gases having been expelled by the heat. Such water 
may be again aerated by allowing it to flow slowly from 
a perforated cask, or through a collander, in many 
fine streams. 

Distillation is the means by which the purest water 
may be obtained. The process consists in boiling the 
water, and in collecting and condensing the steam. 

In this way the solid ingredients are left in the 
boiler. The greater part of the dissolved gases will be 
carried off in the first part of the distillate ; if this 
portion be rejected, the water that subsequently distills, 
may be regarded as approximately pure. 



190 



DOMESTIC SCIENCE. 



The apparatus for distillation (figure 79) consists of 
a boiler a, with a delivery pipe b through which the 
steam is conducted to a spiral tube or worm set in a 
vessel of cold water c ; within the spiral tube, the steam 
condenses to the liquid state, and this water is caught, 
in a suitable vessel d. A stream of cold water is 
supplied to the condenser through the tube e, the surplus 
being carried off through the exit pipe/. 




Fig. 79. 
Apparatus for distillation of water. 

For the distillation of water or other liquids on a 
small scale, the apparatus represented in figure 80 may 
be employed. In addition to its portability this has 
the advantage of being constructed in all its essential 
parts of glass. In the sketch a is a glass flask, con- 
taining water, and heated by a spirit lamp placed below ; 
6 is a delivery tube connected with the condenser c. 



PURIFICATION OP WATER. 



191 



This form of condenser is called from its inventor the 
Liebig condenser ; it consists of a central tube continuous 
with b, and surrounded by a large outer tube, through 
which cold water is flowing. The central tube is 
thus incased in a water jacket, a continuous supply 
being made through d, an escape is provided through 
e. The distillate is caught in /. 




Fig. 80. 
Portable distillation apparatus of glass. 

Great care should be exercised that the distilling 
apparatus be clean, and of such material that the water 
will not dissolve appreciable amounts of its substance. 
Houses that are furnished with steam heating appliances 
may be easily supplied with a sufficiency of distilled 
water. Water that has been distilled with all proper 
precautions may be considered free from all disease 
germs, . and therefore comparatively safe for domestic 
use. Before such water can be relished for drinking 
purposes it must be aerated, and this may be accomplish- 



192 DOMESTIC SCIENCE. 

ed by the same means as employed to aerate the boiled 
water. 

Filtration is often resorted to as a purifying process. 
Many forms of domestic filters are now in the market. 
The manufacturers of these devices usually guarantee 
them to free the water from all suspended and dissolved 
matters ; but such extravagant claims are seldom realiz- 
ed in practice. The commonest form of water filter 
consists of a vessel of wood, stone, or metal, containing 
a slab of porous earthenware, and layers of charcoal, 
magnetic iron oxide, and gravel ; in some filters pound- 
ed glass and sponge are used. Through this the water 
is allowed to percolate, thus imitating in a feeble way 
the grand processes of natural filtration by which foul 
waters become sweet by percolating through the porous 
strata of the earth. A filter, which in service will 
prove fully as efiicient as the high-priced articles offer- 
ed in the market, may be made as follows : Provide 
some water-tight box, cask, or jar of convenient size; 
bore a number of holes in the bottom of the receptacle, 
and place within it alternate layers of recently heated 
charcoal, fine gravel, and sand, till it is half or two - 
thirds full. Pour in at the top the water to be filter- 
ed ; that which first passes through may be somewhat 
turbid, from loose particles derived from the filter ; 
return such to the top. In a short time the filtered 
water will appear perfectly clear, though it may have 
been originally of the foulest kind. Such a filter is of 
service as long as it is clean. The great objection to 
the use of domestic filters is based upon the exceedingly 
small amount of filtering material, and the consequent 
rapidity with which the filters become choked. A 



PURIFICATION OF WATER. 193 

dirty filter — one that has taken from the water all the 
foul matter that it is capable of removing — is a source 
of pollution to the water that subsequently passes 
through. 

The process of filtration is a serviceable one, and 
could it be successfully performed with an apparatus 
of adequate size, it would he regarded as a very 
efficient aid in the purification of water. The writer 
has examined many forms of household filters, and has 
analyzed samples of water both before and after filtra- 
tion through such ; and he has not yet found an 
apparatus of the kind that retains its eflBciency for any 
great length of time ; and most of the filtering devices 
require far more care and attention than the ordinary 
house -keeper is inclined to bestow upon them. And if 
not cared for, they become sources of positive danger. 

A filter, even when working in the best manner 
possible, cannot separate from water its dissolved 
matters ; charcoal, it is true, will take out some portion 
of the ammonia and other gases, but the removal of 
theseisin no case complete, and the amount of dissolved 
solids is in no way diminished by filtration. For the 
removal of mechanically suspended matters, such as 
clay, mud, and sand, the filtration process proves of 
great service ; and in the purification of water on a 
large scale, as for a city supply, filtration is an in- 
dispensable part of the treatment. The water of 
London is filtered by being passed through beds of 
sand and gravel. The average thickness of the sand 
layers is three feet; beneath this are strata of gravel, 
the coarseness increasing with the depth. The water 
upon the filter beds is never allowed to exceed two feet 



194 DOMESTIC SCIENCE. 

in depth. In practice it is found necessary to frequent- 
ly remove the upper layers and to replace such with 
fresh material ; the rapidity with which the filters be- 
come choked is surprising. 

A domestic filter of recent invention is the Pasteur- 
Chamberland device. In this the water is forced through 
at least five partitions of porous earthenware, by which 
treatment it is entirely freed from bacterial organisms. 
Water filtered in this apparatus is completely steriliz- 
ed, though its dissolved solids are not diminished. 
Difficulty is experienced in cleaning this filter. 

For softening waters possessing a high degree of 
temporary hardness, the value of the boiling process 
has been already pointed out. This mode of treat- 
ment, however, is inapplicable on a large scale ; and a 
much cheaper method has been de^'ised. This is 
known as Clark' s process ] and consists in adding lime 
water to the water that is to be softened. It may 
appear to be a strange proceeding, to add lime for the 
purpose of removing a compound of lime, yet the ex- 
planation of the operation is simple. As already ex- 
plained, it is lime carbonate that gives to water the 
property of temporary hardness ; and this substance 
is scarcely soluble at all in pure water ; but it dissolves 
with ease in water containing carbon dioxide. Now 
the lime that is added to such a carbonated water will 
unite with the free carbon dioxide there present, form- 
ing with it insoluble lime carbonate ; at the same time 
the carbonate originally in solution will fall as a sedi- 
ment because the removal of the free carbon dioxide 
robs it of its solvent. In this way it is possible to re- 
duce the hardness of water 70 or 80 per cent. The 



PURIFICATION OF WATER. 195 

addition of the lime water causes a great turbidity 
throughout the liquid, and time must be allowed for 
the sediment to subside before the water can be used. 
In Porter's modification of Clark's process, the water 
is filtered under pressure, the solid particles being thus 
more speedily removed. 

It is claimed that certain chemical substances when 
added to water exert a purifying effect upon it. Of 
these alum is perhaps in commonest use. When mixed 
with certain waters, alum forms a bulky, gelatinous 
precipitate of aluminium hydrate, which in settling 
carries with it much of the matter held in mechanical 
suspension. Good authorities recommend 6 grains of 
alum to the gallon of water as the best proportion . The 
waters of the Seine are used in Paris after clarification 
by this simple process. Tannin exerts a coagulating 
effect upon certain forms of organic matter. The com- 
mon way of adding the tannin is to place oak chips in 
the water, this kind of wood being very rich in the 
astringent named. This treatment is of use only if the 
polluting ingredients are of an albuminoid character ; 
but in waters so contaminated the method is a very 
serviceable one, as the coagulum in forming entangles 
most of the other impurities. Prof. Johnston states 
that the marshy waters of India are rendered potable 
by the use of a nut — strychnos potatorum. The powder 
produced by crushing the nut is rubbed on the inside 
of the water vessel, and the impurities of the liquid 
soon subside. The same authority reports that in 
Egypt the muddy water of the Nile is clarified by the 
addition of bitter almonds.* 

*It is well to read here, the experience of the Israelites, Exodus XVII, 
23—25. 



190 DOMESTIC SCIENCE. 

"And when they came to Marah, they could not drink of the waters 
of Marah, for they were bitter: therefore the name of it was called 
Marah. 

"And the people murmured against Moses, saying, What shall we 
drink? 

"And he cried unto the Lord; and the Lord shewed him a tree, which 
when he had cast into the waters, the waters were made sweet : there 
he made for them a statute and an ordinance, and there he proved 
them." 



MINERAL WATERS. 197 



CHAPTER 23. 



MINERAL WATERS. 



THE term mineral water is applied to any natural 
water that contains so large a proportion of min- 
eral ingredients as to derive therefrom a characteristic 
taste. No clear distinction, other than this, exists 
between potable and mineral waters. 

According to their prevailing ingredients, mineral 
waters are usually classified as sulphur waters, car- 
bonate waters, chalybeate waters, alum waters, and 
saline waters. We will briefly consider each of these 
kinds. 

Sulphur Waters contain a considerable quantity of 
hydrogen sulphide, and this gas posesses such an 
unmistakable odor that no chemical skill is needed to 
determine its presence. Utah furnishes many re- 
markable examples of sulphur springs. The waters of 
the Warm Springs and of the Hot Springs at Salt Lake 
City are rare and wonderful mixtures. 

Carbonated Waters are such as contain an abundance 
of carbon dioxide gas, by virtue of which they dissolve 
large amounts of calcium carbonate and of other car- 
bonates. It has been already shown that the solvent 
power of water for gases is increased by pressure, and 
we may conclude from this, that, within the crust of 
the earth, waters coming in contact with carbon dioxide 
would take into solutions very great proportions of the 
gas. This addition gives the water power to dissolve 



198 DOMESTIC SCIENCE. 

many mineral carbonates of which limestone or cal- 
cium carbonate may be taken as a type. As such 
highly charged water reaches the surface as springs, 
the undue pressure being relieved, most of the carbon 
dioxide escapes, in consequence of which the lime 
carbonates falls from solution in the solid state. This 
may be deposited in such quantities as to form a curb of 
stone around the spring, and to incrust articles immersed 
in the water. Very remarkable carbonated springs 
exist at Soda Springs, Idaho, and at Midway, Utah. 
At the former place the waters are so highly charged 
with carbon dioxide that the escaping gas keeps the 
springs in constant and violent agitation. Any article 
immersed in the water soon becomes coated with a 
deposit of lime carbonate. Such process is sometimes 
incorrectly spoken of as petrifaction ; it is simply an 
incrusting or covering, not a replacing by stone. A 
bunch of grapes or a bouquet of flowers may be com- 
pletely covered in this way, and long after the soft 
fruit and the delicate petals have decayed, the stony 
casing remains, preserving the full form of the original. 
Carbonated waters are of two kinds ; those contain- 
ing much lime in combination are known as Calcium 
Waters ; to this class belong the examples already cited ; 
and waters containing iron compounds as predominat- 
ing ingredients are known as Chalybeate Waters. The 
iron in such waters is present in the form of ferrous 
carbonate, which compound is soluble in water con- 
taining free carbon dioxide, but not in pure water. 
In this respect it resembles the lime carbonate already 
referred to. When the carbon dioxide escapes from 
such water, the iron carbonate is deposited from 



MINERAL WATERS. 199 

solution, under the influence of atmospheric oxygen, 
however, it soon changes to ferric oxide, and appears 
about the springs, and upon objects placed in the 
water as a red or yellow incrustation. Typical illus- 
trations of this class of waters are found in Sevier Co., 
and in Millard Co., Utah. At the former place the 
deposits of ferric oxide are so pure and plentiful, as to 
be used with very little preparation for making paints. 

Alum Waters are rich in iron and aluminium sul- 
phates, and frequently contain small quantities of free 
sulphuric acid. The strong styptic taste of alum is 
characteristic of such waters. Alum springs are not 
of common occurrence in the West. 

Saline Waters contain many earthy salts, among 
which the chlorides of sodium and of calcium predom- 
inate. The celebrated Kissengen and Seltzer Springs 
in Germany, belong to this class, as do also the famous 
Saratoga Springs in the United States. 

To this division of mineral waters belongs also the 
waters of the ocean, and of salt and alkaline lakes. 
The composition of saline waters is very complicated ; 
indeed sea water contains all soluble compounds that 
are found in the earth, and that are capable of existing 
together in the same solution. The prevailing ingre- 
dient is sodium chloride. 

A very concentrated saline water is that of the 
Great Salt Lake, which contains on an average from 
16 to 19 per cent, by weight of solid ingredients, or 
say from 10,000 to 12,000 grains per gallon of water. 
The author collected and analyzed a sample of Salt 
Lake water in December, 1885, and found in it the 
following ingredients : 



200 DOMESTIC SCIENCE. 





Grams 


Per cent. 




per litre. 


by weight 


Sodium chloride 


152.4983 


13.5856 


Sodium sulphate 


15.9540 


1.4213 


Magnesium chloride . 


12.6776 


1.1295 


Calcium sulphate 


1.6679 


0.1477 


Potassium sulphate . 


4.8503 


0.4321 



Total solid matter . 187.6481 16.7162 

The proportion of solid matters in an enclosed body 
of water like the Great Salt Lake is variable according 
to the prevailing climatic conditions. Thus, during 
the dry and warm season, evaporation proceeds much 
more rapidly than water is supplied by the inflowing 
streams, consequently at such times lake water becomes 
more concentrated. During the wet months, however, 
the supply far exceeds the loss by evaporation, and the 
water becomes correspondingly diluted. As a basis 
for comparison with the above figures, there are given 
below the results of an analysis of lake water collected 
in August, 1889. This contained: 





Grams 


Per cent. 




per litre. 


by weight. 


Sodium chloride 


182.131 


15.7430 


Sodium sulphate 


12.150 


1.0502 


Magnesium chloride 


23.270 


2.0114 


Calcium sulphate 


3.225 


.2788 


Potassium sulphate 


5.487 


.4742 


Total solids 


226.263 


19.5576 



The water of the Dead Sea, in Palestine, is still 
more concentrated. An analysis of a sample of Dead 
Sea water collected at a depth of 1110 feet, by Capt. 
Lynch, showed the following composition : 



Per cent, by weight 


Sodium chloride 


7.555 


Potassium chloride 


0.658 


Magnesium chloride 


14.889 


lAme sulphate 


0.070 


Calcium chloride . ■<» 


3.107 


Potassium bromide 


0.137 


Total solids 


26.416 



MINERAL WATERS. 201 

The average temperature of spring water is from 60° 
to 66° F., but mineral springs often far exceed this. 
Indeed some mineral waters are discharged from the 
spring at a boiling temperature. The Hot Springs, 
near Salt Lake City, have a temperature of 128° F. 
The Munroe Springs, in Sevier Co., Utah, discharge 
water at 137.5° F., and certain hot springs, near 
Draper, Salt Lake Co., Utah, emit water at' a tempera- 
ture of 158° F. The constancy of temperature in most 
of these springs is remarkable. Wells says: "There is 
evidence to show that the temperature of some hot 
springs has not diminished for upward of a thousand 
years." 

Before leaving the subject of mineral waters, refer- 
ence should be made to the common belief that all such 
waters are of necessity valuable remedial agents in dis- 
ease. Indeed, there seems to be a popular belief that 
any natural water possessing a particularly disagreeable 
taste or odor is surely good for the body. It is an undeni- 
able fact that many mineral waters possess great thera- 
peutic properties, especially are they valuable for wash- 
ing and bathing in cases of skin diseas.e, gout and 
rheumatism ; and in rare cases it may be wise to ad- 
minister the waters internally ; but there is a reckless 
carelessness now existing as to the use of such waters. 
They should be used in moderation and under skilled 
direction. Mineral water is to be regarded as a medi- 
cine, not as a panacea, and if administered unwisely the 
water may prove positively harmful. 



202 DOMESTIC SCIENCE. 



CHAPTER 24. 

COMPOSITION OF PURE WATER. 

KNOWIMj now that natural waters are never pure, 
and having considered the process of distillation, 
by which chemically pure water may be prepared, it 
would be well now to consider the nature and com- 
position of this purest kind of water. From the earliest 
times of which we have general record till near the end 
of the eighteenth century, water was thought to be an 
element; now it is known to be a compound. Ele- 
ments are simple substances, such as man has never 
yet decomposed into other constituents ; a compound, 
however, is composed of at least two elementary sub- 
stances. As illustrations: gold, silver, iron, nitro- 
gen, carbon, oxygen, sulphur, are elements ; for not one 
of them has ever been decomposed by man. Thus far 
no chemist has been able to produce from pure gold 
anything but gold ; and so with each of the elements, 
of which now between 60 and 70 are known. On the 
other hand, common salt is an example of a compound ; 
it may be separated by chemical means into the two 
elements sodium and chlorine ; carbon dioxide is also 
a compound, it consists of carbon and oxygen. So, 
too, water is a compound, for it may be decomposed 
into the two ingredients, hydrogen and oxygen. 

The decomposition of water may be very beauti- 
fully and instructively illustrated by passing an electric 



COMPOSITION OF PURE WATER. 20B 

current through a quantity of water, and collecting the 
gases that result. If an apparatus similar to that shown 
in figure 81 be employed, the collecting tubes being 
filled with water and inverted over the terminations of 




Fig. 81. 
Electrolysis of water. 

the conducting wires from the battery on the right, 
bubbles will be seen rising in the tubes as soon as the 
current is started. One tube is seen to fill as fast again 
as does the other. The double quantity of gas will be 
proved by investigation to be hydrogen, and the gas 
in the other tube to be oxygen. 

If steam be passed through an iron tube containing 
scraps of iron heated to bright redness, the vapor will 
be decomposed, its oxygen combining with the metal 
in the tube to produce an oxide of iron, and the hy- 
drogen escaping at the open end of the tube, where it 
may be collected. By either of these methods we may 
prove that water consists of the elements hydrogen and 
oxygen. 

The general mode of preparation and the general 
properties of oxygen have been briefly considered in a; 



204 DOMESTIC SCIENCE. 

preceding chapter (see pages 37 and 38). It will be 
well at this stage to review the subject and re-read the 
pages referred to . 

Hydrogen, however, is to us a new element. To in- 
vestigate its properties we should prepare it in larger 
quantity than will be yielded by a weak battery current 
in water. The simplest and for our present purpose 
the best mode of preparing the gas is as follows : Ar- 
range a generating bottle, with funnel, delivery tube, 
pneumatic trough, and collecting bottle. Place within 
the bottle some scraps of zinc ; then adjust the cork 
and pour into the bottle through the funnel tube enough 
dilute sulphuric acid* or muriatic acid to cover the bits 
of zinc to a depth of an inch. Gas will soon collect 
in the inverted bottle ; discard the first bottleful ; it is 
mixed with air ; then collect several bottles of the gas. 
By collecting and examining the hydrogen we shall find 
it to be a colorless gas, and if pure it will be devoid of 
odor, though the impurities of the materials used in its 
manufacture usually impart to the gas a very disagree- 
able smell. It is also very light, exerting a buoyant 
effect on the vessels within which it is confined ; in 
fact, hydrogen is the lightest known substance. Its 
buoyancy may be prettily tested by filling with the dried 
gas a child's toy balloon ; when released this will rise 
swiftly through the atmosphere. 

* Care is called for in diluting sulphuric acid, as great heat Is devel- 
oped in the process. The acid and the water should be measured 
separately— one volume of the former to three of the latter ; the acid 
should then be poured in a small stream into the water, which in the 
meanwhile should be vigorously stirred. The mixture must be made 
in a vessel of glass or earthenware, as the acid will attack wood and 
metal. Remember that sulphuric acid is intensely corrosive and poi- 
sonous. 



COMPOSITION OF PURE WATER. 



205 




Fig. 82. 
Hydrogen burning. 



Hydrogen is also inflammable ; it may be bnrned at 
the mouth of the bottle, as shown in figure 82. A 

better exhibition of the com- 
bustible nature of hydrogen 
may be made by passing the 
gas into a tube that has been 
drawn at one end to a jet. 
The gas as it issues may be 
burned in a continuous flame. 
While the hydrogen jet is 
burning, invert over it a cold 
dry bottle containing air or 
oxygen. A mist appears on 
the inside and drops of liquid 
may collect there. The com- 
bustion of hydrogen then 
marks a combination between this gas and the oxygen 
of the atmosphere, the result of the union is water. 
AVe thus prove the composition of water by analysis 
and by synthesis. By analysis we separate the water 
into its elements, hydrogen and oxygen ; by synthesis 
Ave combine the elements and produce the compound 
water. 

It is remarkable that hydrogen, which burns with 
a very intense heat, and oxygen which is so vigorous 
a supporter of combustion, by their union should form 
a compound possessing the property of extinguishing 
fire. If a stream of oxygen be forcibly driven into the 
midst of a flame of burning hydrogen, the oxyhydro- 
gen flame is produced ; this is attended by the most 
intense chemical heat known. In such a flame, steel wire 
will burn like wood in an ordinary fire ; zinc. 



206 DOMESTIC SCIENCE. 

copper, and all known metals may be deflagrated with 
characteristic flame tints ; even platinum, the most in- 
fusible of metals, may be readily melted by this means. 
Yet the flame is practically non-luminous; its great 
heat may be utilized, however, in raising some incom- 
bustible solid to a state of incandescence. A piece of 
lime or of magnesia introduced into the flame is at once 
raised to a state of dazzling brilliancy. This is known 
as the calcium or Drummond light ^ and is of great ser- 
vice in the operation of optical lanterns, and in other 
cases wherein a particularly brilliant illumination is de- 
sired. 

When oxygen and hydrogen are brought together in 
quantity, and a flame or an electric spark is applied to 
the mixture, a very violent explosion occurs, and water 
is produced by the union of the gases. 

As a result of very accurate experiments we know 
that pure water consists of : 

By volume. By weight. 
Oxygen . . . . l part 8 parts 

Hydi'ogen . . . 2 parts l part 

These proportions are invariable, as indeed are the 
proportions of the constituent parts in any compound. 
In accordance with some great principle, which the 
mind of man has not yet comprehended, the elements 
of matter unite in fixed and unchangeable propor- 
tions. The discovery and proof of this fact is one of 
the greatest achievements of modern science. Not 
only is there order and system in the world of living 
things ; even the dead minerals of earth, and the water 
of ocean and air, each is compounded according to 
governing laws. 



FOOD ITS NATURE AND USES. 207 



I=^jPlK.T III. 



FOOD AND. ITS COOKERY. 



CHAPTER 25. 

FOOD ITS NATURE AND USES. 

CHEMICAL analysis has demonstrated that the 
human body consists of at least fourteen separate 
elements. These are nitrogen, carbon, oxygen, hy- 
drogen, phosphorus, sulphur, sodium, potassium, 
calcium, magnesium, iron, silicon, chlorine, and 
fluorine. Of these the first four are by far the most 
plentiful within the body. It is known that the organs 
of the living body are in ceaseless action, whereby 
great expenditure of force occurs, with consequent loss 
of material." It is therefore necessary that the' system 
be supplied with material from which to repair its vari- 
ous parts ; such supplies we call Food. 

The term food may then be applied to substances, 
that, when taken into the body, serve to nourish its 
tissues, and sustain its vital energy. A perfect food 
would be one that contained all of the fourteen ele- 
ments of the body in a digestible condition, and in the 
proper proportion to supply the various tissues of the 
body. Such a food stuff is not known. Milk ap- 
proaches this ideal standard, yet the proportions in 
which the elements are present in milk fit it to be a 



208 DOMESTIC SCIENCE. 

complete food only for infants ; it is deficient in many 
of the substances required by adults. 

From these statements we will perceive at once the 
necessity of employing a mixed diet, in which we may 
supply with one article, the elements lacking in 
another. According to their composition Foods com- 
prise : — 

I. — Inorganic or mineral substances ; of which the 
principal ones are, (1) Avater, (2) common salt, (3) 
lime, (4) iron, (5) sulphur, (6) phosphorous, (7) 
potassium, (8) silicon, and (9) magnesia. 

II. — Organic substances ; such as are derived from 
plants and animals. These are : 1. Carhonaceous : — 
comprising, (1) amyloids; (2) vegetable acids; (3) 
fats. 2. Nitrogenous substances, sometimes called 
albuminoids, or proteids. Of these we shall con- 
sider: (1) albumen; (2) fibrin; (3) gelatin; (4) 
casein; (5) gluten. 

III. — Auxilliary foods, and condiments. 

A well-regulated dietary should include a proper 
amount of each of these classes of food ; and by an 
instinctive tendency we select and combine foods, to 
accomplish this purpose. As an example, bread is 
rich in starch, a compound of the amyloid group ; it 
contains a small proportion of gluten, which is a 
nitrogenous compound ; but it is very deficient in fat ; 
however, we are prone to add butter to our bread, 
thereby supplying the chief lack. But bread and but- 
ter is an incomplete food ; it is still poor in nitrogen, 
and we usually endeavor to add a nitrogenous element, 
such as meat or eggs at our meals. Potatoes are rich 
in carbon and hydrogen, and in many of the mineral 



FOOD ITS NATURE AND USES. 209 

salts of food ; yet they are very deficient in nitrogen- 
ous substances, and we relish them best with meat. 

It is beyond doubt that many people indulge too 
freely in animal foods ; and others have adopted an 
intemperance of an opposite kind, by abstaining from 
animal matters entirely. Nitrogenous foods we must 
have, and these are advantageously supplied through 
the medium of animal products. It is not necessary 
that flesh be frequently eaten ; milk, butter, cheese and 
eggs are rich in albuminoids. The indications of 
chemical and physiological science and above these, 
the words of the Omniscient* declare that though ex- 
cessive indulgence in animal food is highly injurious, 
yet strict vegetarianism is not a proper course. 

The quantity of food needed for proper bodily sup- 
port varies widely in different persons. The state of 
the person's health, the amount of exercise taken, the 
climate, and many other circumstances unite to regulate 
the demand for food. The natural appetite, un vitiated 
by improper habits, weakening deprivation or unwar- 
ranted excesses, is one's best guide. From numerous 
observations, in many climes and on persons of dif- 
ferent temperaments, it is believed that the average in- 
dividual requirements call for 23 ounces dry solid 

* "Yea, flesh also of beasts and of the fowls of the air, I the Lord 
have ordained for the use of man with thanks-giving: nevertheless 
they are to be used sparingly. And it is pleasing unto me that they 
should not he used only in times of winter, or of cold, or famine." 

Doctrine and Covenants, 89: 12, 13. 

"And whoso forhiddeth to abstain from meats, that man should not 
eat the same, Is not ordaihed of God; for behold, the beasts of the 
field, and the fowls of the air, and that which cometh of the earth, is 
ordained for the use of man for food and for raiment, and that he 
might have an abundance. 

Doctrine and Covenants, 99: 18, 19. 



210 DOMESTIC SCIENCE. 

matter, and 70 to 80 ounces of liquid per day. Dr. 
Hutchinson places the average daily quantity of food 
and drink for a healthy man at 6 pounds ; and divides 
this amount as follows : three and one -half pounds 
from the mineral kingdom, including water and salt ; 
one and one -half pounds from the vegetable kingdom, 
including bread, vegetables and fruits ; one pound 
from the animal kingdom, comprising meat, eggs, 
butter, and such. 

Not all substances containing the elements of the 
human body are fitted for use as food -stuffs. A food 
must contain the essential elements already named, 
in digestible condition. As an example of this necessity, 
consider the case of carbon, which forms so large a 
proportion of most of our ordinary food materials ; 
and is so indispensable to the well-being of the body. 
Carbon in its purest and uncombined state* is entirely 
indigestible, and eoB^equently valueless as food. A 
lump of charcoal contains far more carbon than does 
the same weight of bread ; yet the carbon of the bread 
may be assimilated within the body and become part of 
the tissues ; whereas charcoal, if introduced into the 
stomach, would serve mainly to derange the digestive 
functions. Another example, — nitrogen constitutes 
the larger portion of the muscular tissues, and in 
some proportion it is present in all the bodily parts ; 
there is consequently a great demand for this element. 
The air about us contains nitrogen to the extent of 



*TIie purest carbon exists in a crystalized form as the diamond. 
Other forms of uncombined carbon are graphite or plumbago (the 
"black lead" of pencils^ charcoal, coke, gas-carbon, and lamp black. 
Though these consist almost entirely of this essential element of food, 
yet they are indigestible and consequently unfitted or diet. 



FOOD ITS NATURE AND USES. 211 

four -fifths of its entire weight; yet this atmospheric 
nitrogen is valueless as a food ; it enters the body at 
every respiratory inhalation, and escapes unchanged 
when the breath is expelled. Free nitrogen is not 
assimilated by the tissues : indeed the body seems un- 
able to use the chemical elements as food, until they 
have been brought together as compounds through the 
agency of plaut or animal life. This is true of all 
animal bodies ; they cannot live on unorganized mat- 
ter ; plants may absorb and assimilate mineral sub- 
stances, but animals do not possess this power. In our 
own bodies we can use comparatively complicated 
materials only, — substances that have, been already 
organized under the influences of life. It is a natural 
law that men and animals shall be supported by the 
plant kingdom;* if they feed upon animal bodies, 
these have been nourished by plants, so that their sub- 
sistence comes directly or indirectly from the vegeta- 
ble kingdom. 

Now we may very properly ask, what are the 
essentials of this condition of digestibility in food 
materials? In the first place, to be available as food, 
substances must be readily soluble in the digestive 
fluids. This dissolving action may be in some degree 
imitated outside the body. Chemical mixtures have 
been prepared, analagous in composition to the diges- 
tive juices ; and in these, food materials have been dis- 
solved. Thus one part of the digestive process may 
be carried on in glass flasks before our eyes. Any 
soluble substance may be thus dissolved ; the artifi- 

* "Plants may be considered as the laboratory in which Nature pre- 
pares aliment for animals." Richerand. 



212 DOMESTIC SCIENCE. 

daily prepared mixture acts alike on all soluble 
matters. Not so, however, with the body ; its diges- 
tive apparatus is more complicated than a mere col- 
lection of vessels and tubes ; it is a sensitive, living 
organism, and rejects food that is not pleasing to the 
senses. A food preparation that excites disgust in the 
mind* will be digested only with difficulty, and in 
some cases not at all ; though it may be from a 
chemical point of view very nutritious. 

Several years ago M. M. Edwards and Balzac, two 
French academicians, performed some noted experi- 
ments by feeding dogs on prepared food and carefully 
noting results. The animals were kept for days on a 
preparation of gelatine soup mixed with bread, — 
chemically speaking a very nutritious diet though almost 
devoid of flavor. After a few meals of this stuff, the 
dogs evinced decided dislike, and finally refused to eat 
more of the insipid mess though they were suffering the 
pangs of starvation. The experimenters then mixed with 
the daily allowance of gelatine about two tablespoon - 
fuls of meat broth ; this gave to the soup a pleasing 
flavor ; the dogs ate ravenously of it. One animal 
that had already lost a fifth of its weight under the 
pure gelatine regimen, began immediately to improve, 
and in twenty -three days from the time of the change 
in diet the creature was heavier than before the ex- 
periments were begun. Tests of a similar kind have 
been commenced on human beings. Men have been 

* The digestive organs, as indeed is the case with all other bodily 
parts, are readily affected by the varying conditions of the mind. 
Many a person while eating with relish, has suddenly "lost his 
appetite" under the influence of some strong emotion, either joyous or 
distressing. 



FOOD Its NATURE AND USES. 2l3 

kept on pure chemical preparations, containing all the 
needed elements, but devoid of attractive flavors ; and 
it is beyond doubt that, had the trials been sufiiciently 
prolonged, fatal results would have followed. 

Much of our food has therefore to be prepared for 
the table by a process of cooking. The aim of this 
art is to render food materials more easily digestible 
than they are in a raw and purely natural state, and to 
develop pleasing savors.* Any operation in cookery 
which fails to accomplish both of these ends, but in- 
completel)^ serves its purpose. In its effects upon 
human kind the art of cookery exceeds the influence 
of the fine arts. The use of poorly cooked and insipid 
food has led many people to indulgence in spirituous 
liquors, whereby they hoped to stop the unsatisfied 
craving for a stimulating diet. 

* In their efforts to teach people that mastication and insalivation 
of food are important steps in the digestive process, physiologists have 
long declared that "digestion begins in the mouth;" now, however, this 
saying has with propriety been changed, and may be more properly 
rendered as "digestion should begin in the cook room." 



214 DOMESTIC SClENCfc. 



CHAt'TER 26. 

MINfeRAL INGREDIENTS OF FOOD. 

MINERAL compounds may exist in nature uncoin^ 
bined with any product of animal or plant life ; 
of these common salt and lime are good examples. 
Such substances are found also in the bodies of living 
things, though they there exist largely in an unorganized 
condition. On the other hand, starch, sugar, and al- 
bumen are produced in nature only by processes of 
vital growth as exhibited in the life of animals and 
plants. 

Certain mineral matters are indispensable to the 
growth of the body ; the chief of these are water, com- 
mon salt, and certain compounds of calcium, magne- 
sium, iron, sodium, and potassium. Chlorine is 
present in common salt, and sulphur, phosphorous, 
and silicon are combined with the metals named above. 
Except water and salt, however, these mineral sub- 
stances are absorbed within the body only when in 
combination with organic matters. 

The phosphates of calcium, magnesium, and potas- 
sium are needed for the formation of bone, muscle, 
brain and nervous tissue ; iron is an essential ingredi- 
dient of the red corpuscles of the blood ; the alkalies, 
potash and soda, are required for the blood and for 
many of the solid tissues ; salt is needed, throughout 
the system, and water composes from two -thirds to 
three -fourths of the whole bodily weight. The im- 



MINERAL INGREDIENTS OF FOOD. 215 

portance of the mineral ingredients of food is therefore 
clear. 

Water has already received a somewhat extensive 
treatment, an entire section of this little book having 
been devoted to its consideration. A mere mention at 
this point must therefore suffice. The table on page 150 
shows the proportions of the liquid present in different 
tissues of the body. Water is a universal carrier. No 
solid matter is absorbed in bodies of men, animals, or 
plants, except in solution. 

Common salt is second only to water among the 
mineral elements of food. It exists as an essential 
constituent of all solids and fluids of the human body. 
In the blood, salt is present in greater quantity than any 
other ingredient except water. Dalton gives the fol- 
lowing proportions of salt present in certain parts and 
products of the human body ; the figures state the parts 
of the solid present in a thousand parts of the sub- 
stances named : 





Common salt present 




in 


1000 parts. 


Muscles 


- 


2. 


Bones 


- 


2.5 


Cartilages 


- 


2.8 


Milk 


- 


1. 


Saliva 


- 


1.5 


Bile 


- 


3.5 


Blood 


- 


4.5 


Mucus 


- 


6. 



Salt is present as a natural constituent in many ar- 
ticles of diet ; but to supply the requisite quantity it is 
added to food as a condiment. Moderation in its use, 
however, is essential to health. 

It is possible to acquire a disordered appetite through 
he lavish use of salt ; the craving of condiments once 



216 DOMESTIC SCIENCE. 

started within the body is liable to grow till it becomes 
a serious habit. Salt excites the nerves of taste, and 
renders pleasing, food that otherwise would be insipid 
and tasteless. In the absence of salt, food could be 
but imperfectly digested, and a long continued depri- 
vation of this substance would seriously affect the 
bodily powers, and would lay the system open to the 
inroads of disease. In Holland there was once a law, 
that for certain grave offenses, prisoners should be fed 
on food entirely free from salt ; this was regarded as 
the severest punishment that could be inflicted. Few 
sufferers long survived treatment of this kind ; their 
craving for salt grew so intense as to induce insanity ; 
and their bodies became fatally disordered. Salt is no less 
essential to animals than to the human being. Without 
salt our domestic animals become dull and diseased ; 
their skins grow rough, and much of the hair falls. 
Stock -keepers know from experience the value of pro- 
viding their animals with a free supply of salt. Wild 
beasts whose wariness secures them against being en- 
trapped by tempting baits of food, are readily captured 
at natural or artificially prepared "salt licks." In 
some parts of the world, where salt is scarce, the 
article commands a very high price.* 



* "In man, the desire for salt is so great that in regions where it is 
scarce, it is used as money. In some parts of Africa a small quantity 
of salt will buy a slave, and to say that a man commonly uses salt at 
his meals is equivalent to stating that he is a luxurious millionaire. 
In British India, where the poorer natives regard so few things as 
necessaries of life that it is hard to levy any excise tax, a large part of 
the revenue is derived from a salt tax, salt being something which 
even the poorest will buy. As regards Europe, it has been found that 
youths in the Austrian Empire who have fled to the mountains, and 
there led a wild life to avoid the hated military conscription, will, after 



MINERAL INGREDIENTS OF FOOD. 217 

Yet the natural sources of salt are apparently inex- 
haustible. Vast deposits of it occur in the earth, and 
streams of water flowing to the sea carry the sub- 
stance in solution to their ocean bed. 

Sea water contains on an average three per cent, of 
salt ; the waters of the Great Salt Lake contain over 
eighteen per cent, of their weight of salt. Some varie- 
ties of commercial salt are very impure, containing 
considerable quantities of magnesium and lime in 
combination. 

Utah possesses natural salt in apparently unlimited 
quantities ; vast deposits of rock salt occur throughout 

a time, though able abundantly to supply themselves with other food 
by hunting, come down to the villages to purchase salt, at the risk of 
liberty, and even of life."— Dr. Newell Martin. 

"Animals will travel long distances to obtain salt. Men will barter 
gold for it: indeed, among the Gallas and on the coast of Sierra Leone, 
brothers will sell their sisters, husbands their wives, and parents their 
children for salt. In the district of Accra, on the gold coast of Africa, 
a handful of salt is the most valuable thing on earth after gold, and 
will purchase a slave or two. Mungo Park tells us that with the 
Mandingoes and Bambaras the use of salt is such a luxury that to say 
of a man 'he flavors his food with salt,' it is to imply that he is rich ; 
and children will suck a piece of rock salt as if it were sugar. No 
stronger mark of respect or afEectiou can be shown in Muscovy, than 
the sending of salt from the tables of the rich to their poorer friends. 
In the book of Leviticus it is expressly commanded as one of the ordi- 
nances of Moses, that every oblation of meat upon the altar shall be 
seasoned with salt, without lacking ; and hence it is called the Salt of 
the Covenant of God. The Greeks and Eomans also used salt in their 
sacrificial cakes ; and it is still used in the services of the Latin church 
— the 'parva mica,' or pinch of salt, being, in the ceremony of baptism, 
put into the child's mouth, while the priest says, 'Receive the salt of 
wisdom, and may it be a propitiation to thee for eternal life.' Every- 
where, and almost always, indeed, it has been regarded as emblemat- 
ical of wisdom, wit, and immortality. To taste a man's salt, was to be 
bound by the rites of hospitality ; and no oath was more solemn than 
that which was sworn upon bread and salt. To sprinkle the meat with 
salt was to drive away the devil, and to this day, nothing is more uu- 
Jucky than to spill the salt."— Letheby. 



218 DOMESTIC SCIENCE. 

Sanpete and Sevier Counties, and so in other parts ; 
and the waters of the Salt Lake could supply the world 
with salt for a long period. 

Lime is the most abundant of the solid inorganic 
ingredients of the human body. It is present in all 
solids and fluids of the system though in widely vary- 
ing quantities. It occurs mostly as calcium phos- 
phate, and less abundantly calcium carbonate. 

According to Dalton, the following figures show the 
quantity of calcium phosphate in 1000 parts of the 
tissues and fluids named : 





Lime phosphate 




in 1000 parts. 


Teeth 


650 


Bones 


550 


Cartilages . 


40 


Muscles 


2.5 


Blood 


0.3 


Gastric juice 


0.4 



Lime imparts strength and rigidity to the bony skel- 
eton ; a deficiency of it causes pliancy and disease of 
the bones. In early life, the bones are naturally soft, 
because, ossification being then incomplete, the ani- 
mal matters of the bones exceed in quantity the min- 
eral substances ; children, therefore, require a com- 
paratively large amount of lime salts ; and this is best 
supplied through means of a generous diet of milk and 
grain preparations, with a very moderate allowance of 
other animal food. 

The hardest substance of the body is the enamel of 
the teeth; this consists mostly of lime salts, the phos- 
phate, being in excess. A common and an instruc- 
tive demonstration of the importance of lime com- 
pounds in the bones, may be made hj soaking a bone 



Mineral ingredients of FOOt>. 



219 



in dilute acid, thereby removing the mineral substances. 
Procure a rib for the purpose ; it being in shape long 
and slender will be well adapted. Place the bone in 
a mixture of one part muriatic acid and fifteen parts 
water ; allow it to remain in the acid during a few 
days, then remove and wash it. The bone will be 
found soft and pliable, so that it may be easily bent 
in any desired form, or even tied in a knot. The ani- 
mal tissue that remains after the treatment with acid 
will dry and become hard and transparent. 





Fig. 83. 
Bone of human arm. Same bone after treatment with acid. 



Figure 83 represents the large bone of the human 
arm ; and the same bone after the removal of its 
mineral matter by treatment with acid. It has been 
bent and tied. 

Iron constitutes about one -thousandth part of the 
weight of the blood ; it is essential to the red color of 
the blood corpuscles. In the entire body there is about 
five drachms of iron. When the blood is deficient in 
this element, it becomes pale in color, the skin as- 
sumes an unnatural pallor, and the bodily strength 
very rapidly diminishes. It is then a common practice 
in medicine to administer iron in a soluble form, usu- 



220 DOMESTIC SCIENCE. 

ally as the tincture of iron per -chloride, or as iron 
citrate. 

Iron is supplied in the food through the medium of 
milk and eggs, and many vegetable articles of diet. 

Sulphur and Pliospliorus, though present in very 
small quantities, are still essential within the body. 
These substances occur mostly in combination, as 
phosphates and sulphates of calcium, magnesium, 
potassium, and sodium. Dr. Foster says: "The ele- 
ment phosphorus seems no less important from a bio- 
logical point of view than carbon or nitrogen. It is as 
absolutely essential for the growth of a lowly being 
like penicillium* as for man himself. We find it 
peculiarly associated with the proteids, apparently in 
the form of phosphates, but we cannot explain its 
role. The element sulphur, again, is only second to 
phosphorus, and we find it as a constituent of nearly 
all proteids, but we cannot tell exactly what would 
happen to the economy if all the sulphur of the food 
were withdrawn." 

The compounds of magnesium^ potassium, sodium, 
and silicon, which are called for in much smaller quan- 
tity than are the substances already named, are pres- 
ent in ordinary food stuffs, and are seldom found in 
insufiicient quantity within the body. 

The mineral elements of food as a rule do not un- 
dergo chemical change by decomposition or combina- 
tion within the body. They are absorbed with the 
food and enter the tissues, forming an indispensable 

* Penicillium— the common green mold or mildew, so common in damp 
situations, as upon old shoes, bread, vegetables, fruits, and jams. It is 
a living thing; a plant belonging to the order otfunffi. 



MINERAL INGREDIENTS OF FOOD. 221 

part of the body substance ; then they are removed by 
the processes of secretion, and their place supplied by 
more particles of the same kind. The changes pro- 
duced upon mineral matters by the processes of cook- 
ing are so slight as to be inconsiderable for our present 
purpose. 



222 DOMESTIC SCIENCE. 



CHAPTER 27. 

ORGANIC INGREDIENTS OF FOOD ; CARBONACEOUS FOODS ! 
STARCH, SUGAR, GUM. 

CERTAIN food materials occur in nature as products 
of animal or vegetable life only ; such are called 
organic foods, to distinguish them from mineral matters. 
The organic ingredients of food may be classified as 
shown on page 208. 

Carbonaceous food substances claim our attention 
first. These are so named because of the predomin- 
ance of carbon as an element of their composition. The 
amyloids, such as starch and sugars, consist entirely of 
carbon, hydrogen, and oxygen ; they are therefore 
known chemically as carbohydrates. The fats contain 
the same elements, though in different proportions, the 
oxygen being present in them in very small quantity. 

The AMYLOID GROUP of food substances include 
starch, sugar and gum, of each of which there are many 
varieties. Starch in its prepared form appears as a 
white powder, possessing a gritty feel if rubbed be- 
tween the fingers. When viewed through the micro- 
scope the powder will be seen to consist of minute 
rounded grains, the exact form varying in starches from 
different sources. Figure 84 represents starch granules 
from many plants; a from the potato; these parti- 
cles are somewhat like clam shells, the surface of each 
being marked by waving lines, concentric about a point 
known as the hilum; this point marks the place at 
which the grain was originally attached to the cell wall. 



ORGANIC INGREDIENTS OF FOOD. 



223 



Grains of potato starch vary in size from ^ to ^ 
of an inch in diameter. The grains of wheat starch are 









/ 



m 



^ e 









6> 









c/ 



d®, 












(^ 



(2f 



6 



■% a> 



/ 



>'^.fii,'#^,^^ 



<^ 






^1 



/^ 



C^ri, (3 



-# (fs ^^ C'"*' 



Fig. 84. 
Starcli granules. 



224 DOMESTIC SCIENCE. 

smaller than the preceding ; they rarely exceed -^ 
inch in diameter, and from that thev vary to -^. Starch 
granules from wheat present a more perfectly cylindri- 
cal outline (7^) ; many of the grains are flattened, so 
that in a side view they present a narrow edge. 

Starch from oats consists of large, compound gran- 
ules, which under pressure may be readily broken into 
sections. Starch grains from maize, or Indian corn, 
are shown at c, and d grains from rice. In both corn 
and rice starch the grains are irregular in form, many 
of them presenting an angular outline. At /is shown 
the appearance of starch grains from peas, and g from 
beans. Starch is of common occurrence in plants ; in- 
deed, no plant entirely devoid of it has yet been found. 
At certain seasons the substance accumulates within 
the body of the plant in great quantity ; starch is the 
form in which the plant stores its food material for 
future growth. Its wide occurrence is shown by the 
following table : 





Average percentage 






of starch. , 


Potatoes - 


- 


15.70 


Peas 


- 


32.45 


White beans 


- 


33.00 


Kidney beans 


- 


35.94 


Buclcwtieat 


- 


52.00 


Kye flour - 


- 


56.00 


Oatmeal - 


- 


59.00 


Wheat kernel 


- 


59.5 


Rye meal - 


- 


61.07 


Barley meal 


- 


67.18 


Wheat flour 


- 


72.00 


Maize 


- 


80.92 


Rice 


- 


85.07 



Certain articles of diet consist almost entirely of 
starch, such are corn starch, arrowroot, sago, tapioca 
and rice ; these will receive our future attention. For 



ORGANIC INGREDIENTS OF FOOD. 



225 



the present let us examine the living plart and inform 
ourselves of the way in which starch is stored within 
it. The microscope has revealed the important fact 
that all plant tissue consists of thin -walled enclosures 
known as cells, and within these the secretions peculiar 
to the plant are formed. Figure 85 shows three sec- 
tions of plant tissue containing starch granules ; the 
upper left hand sketch illustrates a potato cell ; the 




Fig. 85. 
Plant cells filled with starch. 

next section is that of an oat seed, and the lower one 
represents a wheat kernel. 

Starch is scarcely soluble at all in cold water ; but, 
when heated in water near the boiling point, the grains 
absorb liquid, and burst, forming a jelly or paste. In 
this form starch is of use for laundry purposes ; this 
"boiled starch" is not a true solution, however; the 
starch and water may be almost entirely separated by 
freezing. The fact that cold water has so little sol- 
vent effect on starch, suggests a method for its prepar- 
ation. 



226 DOMESTIC SCIENCE. 

Grate some potatoes to the condition of a fine pulp ; 
place this within a bag of coarse muslin ; immerse in 
water and knead well under the liquid. The water 
soon becomes milky, and after a time a white powder 
settles to the bottom. This is starch; it may be re- 
moved from the water and dried. Wheat flour may be 
treated in the same way and starch procured from it. 

Siigar is a sweet vegetable product, found in the 
juice of cane, the roots of beets, the' sap of certain 
trees, and in many fruits. In a chemical sense there 
are many kinds of sugar, the chief of which are sac- 
charose or cane sugar, glucose or grape sugar, levulose 
or the sugar of fruit, and lactose or su^ar of milk. 

Saccharose is found in a fairly pure form, as loaf and 

granulated sugar of commerce, though a still purer 

kind is met with in the uncolored and crystallized rock 

candy. This is the most sweetening of all common 

sugars. It is prepared chiefly from the sugar cane, 

sugar beet and sugar maple. It may also be produced 

from sorghum, and in smaller quantity from the juices 

of mauy other plants, as maize, parsnijDS, carrots. The 

following table shows the proportions of sugar present 

in different products : 

Per cent, 
of sugar. 

Indian corn - - - - 1.5 
Peas ----- 2. 

Eyemeal - - - - 3.2 

Oatmeal - - - - 4.8 

Barley-meal - - - - 5.2 

Wheat flour - - - - 5.4 

Beets - - - - 9.0 

Ripe pears - - - - 11.5 

Ripe peaches - _ . i6.5 

Ripe cherries _ _ _ is.i 

Figs - - - - 62. 



ORGANIC INGREDIENTS OF FOOD. 227 

Saccharose melts at about 356° F., and if cooled 
rapidly from that temperature it forms a granular mass 
known as barley sugar ; of this the prepared candies 
largely consist. If a higher heat be applied to sugar 
it becomes burnt or caramelized. Caramel is used as 
a coloring agent in cooking. 

Glucose or grape sugar occurs in many fruits, being 
specially plentiful in grapes. This sugar does not 
readily crystallize, and its sweetening power is not more 
than three -fifths that of cane sugar. It may be pre- 
pared from starch by simple processes. Several large 
establishments in the United States are devoted entirely 
to the manufacture of glucose. The material used for 
the purpose is Indian corn. As a result of extended 
tests it is believed that glucose is no more unwhole- 
some as an article of food than is true cane sugar, 
though doubtlessly extensive frauds are in operation by 
which saccharose is largely adulterated with the cheaper 
glucose. The transformation of starch into glucose 
takes place in the sprouting of seeds ; plants store their 
food supplies within the seeds as insoluble starch ; 
when germination begins the starch becomes glucose, 
and is easily absorbed and assimilated by the growing 
plant. It is an easy matter also by chemical means to 
transform saccharose into a mixture of glucose and 
levulose ; but thus far no satisfactory method of making 
the reverse transformation, namely, from glucose to the 
sweeter saccharose, has been devised. 

The preparation of saccharose from vegetable liquids 
is an instructive process. The juice is obtained by 
pressure ; it is then mixed with a quantity of lime to 
neutralize any free acid present and to assist in settling 



228 DOMESTIC SCIENCE. 

the impurities ; the clarified juice is then evaporated, 
and the product is crude, brown sugar, commonly 
known as Muscovado sugar. This is to be purified. It 
is dissolved in water and the solution is decolorized by 
being heated with bone black or animal charcoal. It is 
then clarified by an addition of albumen, usually in the 
form of blood, this by its coagulation and settling car- 
ries most of the impurities to the bottom. The liquid 
is then evaporated, and the crystallizing sugar is separ- 
ated by centrifugal power. To prevent burning of 
the sugar, the evaporation is conducted in vacuum 
pans, which are vessels so constructed as to cause the 
removal of the vapor as fast as formed ; by these 
means the pressure upon the liquid is reduced and the 
boiling proceeds at a much lower temperature. The 
purified article appears as loaf or granulated sugar. 

The syrup remaining after the crystallization is 
known as molasses, though much molasses is made 
from sorghum juices without any separation of sugar. 
The diflSculties thus far experienced in the preparation 
of sugar from sorghum have been largely due to the 
ready inversion of the contained saccharose, by which 
it becomes changed into glucose and levulose. These 
obstacles have been mostly overcome during recent 
years, and a very good article of sugar is now obtain- 
able from sorghum cane. 

Vegetable gums are by no means inconsiderable as 
elements of food, though in this country they are 
seldom used in special food preparations. The prin- 
cipal gums that enter into the composition of food 
stuffs are arabin or gum-arabic, cerasin, the gum from 
cherries and plums, and vegetable mucilage which oc- 



ORGANIC INGREDIENTS OP FOOD. 



229 



curs in almost all kinds of plants. Gum is present in 
considerable quantity in grains and in preparations 
from them. The following table, according to Von 
Bibra, shows the proportions of gum in several dry 
plant products : 





Per cent, of 




gum. 


Wheat kernel . 


4.50 


Wheat flour . 


6.25 


Wheat, bran . 


8.25 


Rye kernel 


4.10 


Rye fiour 


7.25 


Rye bran 


10.40 


Barley flour . 


6.33 


Barley bran . 


6.88 


Oatmeal 


3.50 


Rice flour 


2.00 


Millet flour . 


10.60 


Maize meal 


3.05 


Buckwheat flour 


2.85 



By heating starch to a temperature of 300° F. it un- 
dergoes a remarkable change, assuming a yellow color 
and becoming readily soluble in water. This substance 
is a kind of gum, and has been named dextrin. It is 
largely used as a dilutent for other gums, and in a pre- 
pared state as a mucilage is sold as British gum, Alsace 
gum, and starch gum. It has strong adhesive prop- 
erties. 



230 DOMESTIC SCIENCE. 



CHAPTER 28. 

CARBONACEOUS INGREDIENTS OF POOD, CONTINUED. 
VEGETABLE ACIDS AND FATS. 

IN composition, the vegetable acids are closely allied 
to the sugars and starches already considered. The 
name vegetable acids expresses at once the nature and 
occurrence of the substances ; they give sourness to 
fruits and many vegetable products, though they are 
present in plants in very small proportion only. In 
food they serve to impart a pleasant pungent taste, and 
within the body, they undergo ultimate digestion as 
do the starches and the sugars. The chief of the veget- 
able acids are citric acid, tartaric acid, malic acid, and 
oxalic acid. 

Citric acid is the sour principle of lemons ; it occurs 
also in oranges, citrons, cranberries, and unripe tomatoes ; 
associated with other acids it is found in strawberries, 
raspberries, currants, gooseberries, and cherries ; and 
in smaller quantity, combined with lime as calcium 
citrate, it is found in artichokes, onions, and beets. 
Citric acid is an ingredient of many common sour and 
effervescent beverages. 

Tartaric acid^ is the prevailing acid of grapes ; it is 
found, too, in many other fruits ; and in the combined 
state as tartrates of potassium and calcium, it is also 
found in potatoes, pine apples, cucumbers, and in 
sumach berries. The chief source of the acid is argol 
or crude potossium tartrate, which collects as sediment 



VEGETABLE ACIDS AND FATS. 231 

in vats of fermenting grape juice. Purified potassium 
tartrate is known as cream of tartar. In a pure state 
tartaric acid crystallizes in clear large plates ; it is in- 
tensely sour to the taste, and is used in preparing 
effervescing drinks. For such purposes, however, it is 
but an inferior substitute for citric acid. 

Malic acid is the chief cause of sourness in apples, 
small fruits, plums, and cherries. It is widely distribut- 
ed throughout the vegetable kingdom, especially in 
immature fruits. In combination with potassium as 
potassium malate it is abundant in the juices of rhubarb. 
The acid is seldom prepared in a pure state, as but 
little practical use has been found for it ; it may how- 
ever be purified as a white crystalline solid very readi- 
ly soluble in water, the solution possessing an intense- 
ly sour taste. 

Oxalic acid exists in sorrel, rhubarb, and many other 
plants. It is usually found in combination with 
calcium and potassium as oxalates of those metals. 
Potassium oxalate has long been sold as "salts of 
sorrel," and has found domestic application as a means 
of removing ink stains and iron -mold spots from 
clothes. Purified oxalic acid appears as transparent 
crystals ; it is intensely poisonous, and many fatalities 
have resulted from its use. It has many times been 
mistaken for Epsom salts, which indeed it greatly 
resembles. 

Another substance very closely akin to the vegetable 
acid just considered is Pectin or vegetable jelly. This 
is largely prepared from fruits by heating them with 
water, sweetening and straining. The solution be- 
come a jelly in cooling. The acids present in jelly so 



232 DOMESTIC SCIENCE. 

prepared arc known as pectic and pectosic acids. These 
by long continued heating become transformed into 
metapectic acid which is so readily soluble that a solu- 
tion containing it no longer solidifies on cooling. This 
is Avell known to housewives, who have tried to con- 
centrate a fruit jelly by long continued heating ; usually 
a syrupy liquid only is obtained. It is a general 
belief that sugar is essential to the production of a 
jelly from vegetable juices ; the sugar, beside its 
sweetening effect, absorbs the excess of water present, 
and leaves the pectic and pectosic acids free to solidify 
by cooling. 

An acid of vegetable origin, though not occurring 
free in nature is acetic acid, the sour substance in 
vinegar. This will receive brief attention in the 
chapter on "auxilliary foods.'' 

It has already been stated that the vegetable acids 
are allied in chemical nature to the amyloids already 
described. Examples of the transformation of acids 
into starch and sugar are common in nature. Thus, 
in the green state, apples are intensely sour ; as the 
ripening process proceeds however, the sourness is less 
marked, and a chemical examination shows an increase 
in sugar, and a corresponding diminution of malic 
acid and starch. 

The next group of carbonaceous food elements, com- 
prises Fats and Oils. These substances consist of 
carbon, hydrogen, and oxygen, the last named element 
however, being present in very small proportion only. 
The fats are therefore mostly composed of carbon and 
hydrogen, and are spoken of as hydro -carbons. Some 
fats both of animal and of vegetable origin, are 



VEGETABLE ACIDS AND FATS. 233 

characterized by containing a small amount of phos- 
phorus ; these are known as phosphorized fats. The 
oil from peas contains 1.17 per cent, phosphorus ; bean 
oil .72 per cent. ; vetch oil .5 per cent. ; barley oil .28 ; 
rye oil .31 ; oat oil .44. These figures are given on 
the strength of Toepler's experiments. 

There appears no essential difference of composition 
between the solid fats, and the liquid oils, the con- 
sistency depending greatly upon the temperature. 
Tallow may be reduced by warming to a mobile liquid ; 
and olive oil may be solidified by cold. In Africa, the 
fat of the palm tree is in the state of liquid palm-oil ; 
with us the same substance is semi -solid and is known 
as palm -butter. 

Both the animal and vegetable kingdoms supply us 
with requisite food fats. Of common oils there 
are two main groups, the fixed oils, and the volatile or 
essential oils. The former are the more important as 
food elements ; they may be recognized by their power 
of producing permanent grease stains when placed upon 
paper ; even gentle warming fails to remove such spots. 
The volatile oil if smeared on paper, produce but 
temporary stains : these entirely disappear by heating. 
Some volatile oils do slight service as auxilliary foods ; 
for the present we confine ourselves to a consideration 
of fixed oils and fats only. 

Vegetable fats are largely obtained from seeds ; good 
examples are furnished by the oily seeds of flax, colza, 
cotton, peanut, butternut, and sunflower. The 
following specifications show the amount of oil present 
in certain vegetable products : 



234 



DOMESTIC SCIENCE. 



Meadow grass 
Meadow hay 
Clover hay 
Wheat bran . 
Wheat kernel 
Wheat flour 
Maize kernel 
Pea 
Rice 

Buckwheat 
Olives 
Cotton seed 
Flax seed 
Colza seed 
Cocoanuts 
Filberts 



Fat is also present 



Per cent, of oil. 
0.8 
3.0 
3.2 
1.5 
1.6 
1.5 
8.0 
3.0 
0.8 
0.4 
32.0 
34.0 
34.0 
45.0 
47.0 
60.0 

in common articles of animal 



food, as these figures will show : 



Cows' milk 
Goats " 
Human milk 
Ordinary meat 
Liver of ox 
Yolk of eggs 



Per cent, of fat. 

3.13 

3.32 

3.55 
14.03 

3.89 
28.75 



There is a strong prejudice, none the better because 
popular, against the use of vegetable oils in food. As 
a rule we prefer the poorest of lard, to the purest oils 
of olive and palm ; yet as cooking media the plant oils 
are in all respects superior. Cotton -seed oil has been 
proved to be nutritious and wholesome ; it has lately 
found extensive use in the preserving of fish, and cot- 
ton planters now find the seed of their crop almost as 
valuable as the fibre. True, the price of refined 
vegetable oil is at present high when compared with 
the cost of animal fats ; the crude oil, however, is far 
cheaper than the unrefined animal product, and as 
soon as a demand arises for pure vegetable oils, there 
will be no lack of supply at a cheap rate. 



Vegetable acids and fats. 235 

The chief of common fats are enumerated and briefly 
described below : 

Olein is abundant in ordinary oils ; being the most 
fluid of common fats, it may be prepared in quantity 
from oils and the softer fats. 

Palmitin is plentiful in African palm oil ; it occurs 
also in beeswax and tallow. It is fluid only during 
warm weather, or under the influence of artificial 
heat. 

Stearine may be prepared from tallow. It is 
present in all common fats, and being-solid at ordinary 
temperatures imparts solidity to other fats. 

Fatty substances are generally insoluble in water ; 
yet under certain conditions, oils may be suspended in 
water in a very finely divided state ; such a mixture is 
known as an emulsion. A little oil shaken up in water 
to which a minute quantity of soda had been added, 
will exemplify an emulsion. The microscope shows in 
such a mixture the oil drops still separate and perfect. 
Milk is an example of a natural emulsion. 

A farther characteristic of all fats is their property 
of forming soaps with the alkalies. Fats constitute a 
very important part of food material. When eaten, 
fatty matters develop great bodily warmth, they are 
therefore well adapted as a diet for cold climes. 
Under the influence of severe cold, a strong, natural 
craving for fat is developed. Seamen, wintering in 
arctic regions eat fats with relish. The Esquimaux in 
their wintry home devour immense quantities of 
oleaginous matter.* 



*Dr. Hutchinson says, "The Esquimau consumes daily from ten to 
fifteen pounds of meat or blubber, a large proportion of which is fat. 



236 DOMESTIC SCIENCE. 

The Laplander will drink train oil, and regards tallow candles as a 
great luxury." 

The need of fat in the food of children is very great. Dr. Edward 
Smith says on this subject, "Children who dislike fat cause much 
anxiety to parents, for they are almost always thin, and if not 
diseased, are not healthy. If care be not taken they fall into a 
scrofulous condition, in which diseased joints, enlarged glands, sore 
eyes, and even consumption occur; and every etfort should be made to 
overcome this dislike. If attention be given to this matter of diet, 
there need be no anxiety about the possi]5ility of increasing the 
(luantity of food consumed; whilst by neglect, the dislike will probably 
increase until disease is produced. The chief period of growth, viz.— 
from seven to sixteen years of age— is the most important in this re- 
spect, for a store of fat in the body is then essential. Those who are 
inclined to be fat, usually like fat in food, and then it may be desirable 
to limit its use. Some who cannot eat it when hot like it when cold, 
and all should select that kind wliich they prefer." 



NITROGENOUS INGREDIENTS OF FOOD. 237 



CHAPTER 29. 

nitrogp:nous ingredients of food. 

NITROGEN is an essential constituent of most tis- 
sues of the human body ; there is need therefore 
of nitrogenous food to nourish tlie parts. The im- 
portance of foods of this nature is so great that they 
have been called flesh formers. We must not be led 
by this appellation to the extreme belief that no food 
material devoid of nitrogen is of value ; starches and 
sugars, gums and fats, are of indispensable service in 
sustaining bodily heat, and they serve also as sources 
of actual energy, which manifests itself as muscular 
force. It is a plain fact nevertheless, that non-nitro- 
genous matter can but imperfectly build up tissues of 
which nitrogen forms an important constituent. From 
the general resemblance of all nitrogenous food com- 
pounds to the first and commonest of the group they 
are often called Albuminoids, sometimes also Proteids; 
this last name is derived from the Greek and signi- 
ties "first" or "most important," having reference 
here to the imperative need of nitrogenous substances 
within the body. The albuminoids are composed of 
nitrogen, carbon, hydrogen and oxygen ; many of 
them contain also a small proportion of sulphur. 

Albumen may properly be studied as the first of the 
group; it is found in an aknost pure condition, ex- 
cept for its admixture with water, in the white of Qgg. 
The word "albumen" is of Latin derivation, — albus, 



238 DOMESTIC SCIENCE. 

meauiiig white, and is so applied because of the white 
color assumed by the substance when heated. A care- 
ful study of the properties of albumen is essential to 
an understanding of many operations in cooking. 
Procure a fresh egg, separate the yolk from the white, 
and place the latter in a glass test tube, insert a ther- 
mometer, and immerse the lower part of the tube in 
water which is being gradually heated. As the tem- 
perature within the tube ranges from 130° to 140° F., 
white, opaque fibres appear in the substance ; these 
increase till the whole mass of albumen has been con- 
verted into a white, semi -solid coagulum. This change 
will be complete when the temperature has risen to 
170° F., and any greater heat will harden the egg 
substance, and if long continued will convert it into 
a tough, apparently indigestible mass. It is plain 
then that a temperature of 170° F. is sufficient to prop - 
erly coagulate the albumen. 

In the liquid condition, albumen is soluble in water ; 
after coagulation, however, it is almost entirely insol- 
uble. As an illustration of this, the white of egg may 
be shaken or stirred in cold water, and completely 
dissolved therein ; on heating the liquid to the proper 
temperature the albumen will appear in the solid 
form as flakes. Albumen as a food is mainly de- 
rived from the animal kingdom, though the substance 
exists in the juices of plants, and in many seeds and 
grains. 

Fibrin, another albuminoid, is present in considera- 
ble quantity in many animal fluids. The clotting of 
blood is due to the spontaneous coagulation of the 
contained fibrin. To procure fibrin for examination. 



NITROGENOUS INGREDIENTS OP FOOD. 



239 



place a quantity of fresh blood in an open vessel, agi- 
tate or whip the liquid with a wisp of fine twigs or 
wires ; the fibrin will gather upon the bundle in the 
form of stringy, semi-liquid masses. Blood so de- 
fibrinated has lost its power of clotting.* 

The separated fibrin may be washed and purified ; 
then it appears of a yellowish color, and is soluble in 
hot water. Take now a bit of raw lean meat; thor- 
oughly wash it in water ; the liquid becomes colored 
from the red juices taken from the meat, and that 
which remains is of a purplish tint and a fibrous struc- 
ture. These fibres consist mainly of animal fibrin, 

though the 
distinguish i n g 
name of myos- 
in has been ap- 
plied to such. 
Fig. 86 is a 
sketch of the 
magnified fibres 
of lean meat. 

Fibrin is also present in certain plants, especially in 
juices. If turnip juice be exposed to the air, after a 
short time it deposits solid flakes of coagulated fibrin. 




Fig. 86. 
Fibres of lean meat. 



* Exposure to the air induces the clotting of Wood. This change is 
caused hy the hardening of the fibrin— a constituent of the plasma— 
by which the blood corpuscles are entangled so as to form a plug or 
clot. A yellowish liquid separates as the clot forms ; this is known as 
blood-serum. The benefits resulting from this property of blood can 
scarcely be over-estimated. In the case of a severed vein or artery, the 
flow is checked by clotting, while the healing of the vessel is in pro- 
gress. Did this nroperty not exist In the blood, bleeding could be 
stopped only by artificial means. Among birds the clotting of blood is 
especially rapid. This feature is a great benefit to these winged creat 



240 DOMESTIC SCIENCE. 

For purposes of distinction this has been named vege- 
table fibrin. 

Gelatin is a very important member of the albumi- 
noid family of foods. It is present in most of the tis- 
sues of the animal body, including bones and cartilage. 
In a purified form gelatin is insoluble in cold water, 
though it dissolves readily in hot water, and the solu- 
tion on cooling assumes the condition of a jelly. Gel- 
atin is the chief ingredient of all animal jellies, one 
ounce of pure gelatin is capable of combining with 
one and a half pounds of water to form jelly. The 
purest commercial form of gelatin is isinglass, which is 
a preparation from the swimming bladders of fishes. 
Specimens of gelatin from different sources possess 
widely varying degrees of solubility. Calves' foot 
jelly is a delicious food ; jelly made from the feet of 
<ows is far less prized because of its inferior solubility. 
The turtle's body is rich in gelatin, and as a conse- 
quence it is in great favor as a prime ingredient of 
soup ; a somewhat inferior and much less expensive 
luxury is mock turtle soup, which contains gelatin from 
pigs' feet, calves' heads, and the like. 

The material of which the edible birds' nests are 
composed is a kind of gelatin. These nests are con- 
structed by a species of swift* inhabiting the coasts of 

ures, for the great muscular exertion of flying would cause profuse 
bleeding from very small wounds, were it not for the stopping of the 
injured vessels by the blood clots. In this we see Divine provision 
even for the accidents to which animals and men are subject. 

* This variety of swift, the "esculent swallow" as it is commonly 
called, delights to build in caves ; and it is stated that a single cavern 
in Java, to which the birds have taken a decided liking as a place of 
abode, brings its proprietor an income of $25,000 a year rental, the 
sole value of the place depending upon the nests therein constructed. 



NITROGENOUS INGREDIENTS OF FOOD. 241 

China, Sumatra, and Java. The birds produce large 
quantities of slimy saliva, which, on drying, becomes 
solid and transparent gelatin ; it is readily soluble in 
hot water, the solution constituting the much-prized 
jelly. 

The value of gelatin as an article of food has been 
made the subject of special inquiry by certain mem- 
bers of the French Academy, as already stated (page 
212). M. Edwards, one of the experimenters, draws 
the following conclusions from his observations and 
tests. The English construction is the translation of 
Mr. Mattieu Williams: "1. That gelatin alone is in- 
sufficient for alimentation. 2. That although insuffi- 
cient, it is not unwholesome. 3. That gelatin con- 
tributes to alimentation, and is sufficient to sustain it 
when it is mixed with a due proportion of other pro- 
ducts which would themselves prove insufficient if 
given alone. 4. That gelatin extracted from bones, 
being identical with that extracted from other parts, 
and bones being richer in gelatin than other tissues, and 
able to afford two -thirds of their weight of it, there is 
an incontestible advantage in making them serve for 
nutrition in the form of soup, jellies, paste, etc. ; 
always, however, taking care to provide a proper ad- 
mixture of the other principles in which the gelatin soup 
is defective. 5. That to render gelatin soup equal in 



This cave the swifts share good naturedly with the bats, the latter 
holding possession during the day, and the birds occupying the lodg- 
ings at night. In shape the nests resemble hanging bags or pouches, 
and they are held firmly against the wall through the adhesive proper- 
ties of the salivary mucus. Birds' nest soup ranks among the costliest 
of table delicacies of its class ; the clean dry nests sell in the market 
for their own weight in silver. 



242 DOMESTIC SCIENCE. 

nutritive and digestible qualities to that prepared from 
meat alone, it is suflScient to mix one -fourth of meat 
soup with three -fourths of gelatin soup; and that, in 
fact, no difference is perceptible between soup thus 
prepared and that made solely from meat." 

We are then to regard gelatin as a very efficient food 
when properly flavored by admixture with other sub- 
stances ; alone it is repulsive to the system. Gelatin 
is furnished by the animal kingdom only. 

Casein is the chief albuminoid found in milk and 
cheese. In the former it exists to the extent of from 
three to six per cent., and constitutes the greater part 
of the curd of milk. In fresh milk the casein is held 
in solution ; by coagulation, however, as in cheese 
making, the substance is rendered almost entirely in- 
soluble in water. The coagulation of casein in milk 
may be effected by adding a small quantity of acid ; 
though the change is best brought about by the addi- 
tion of rennet, which is an infusion of the mucous lin- 
ing of a calf's stomach. Unlike albumen, casein is 
not coagulable by heat. A common example of casein 
solidifying in the presence of an acid is seen in the 
spontaneous souring of milk ; under particular circum- 
stances the sugar in the milk is decomposed, lactic acid 
being formed in the process ; this acid causes a speedy 
precipitation of the casein as a voluminous curd. When 
milk is curdled through the addition of rennet, the 
casein carries with it from solution many of the min- 
eral salts, notably the phosphates, which were origin- 
ally present in the milk ; precipitation by acid, how- 
ever, removes these substances from the curd, and 
they are lost in the whey. Cheese formed by the 



NITRO&ENOUS INGREDIENTS OF FOOD. 



243 



first method therefore is superior to that made by the 
addition of acid. 

When separated from the other ingredients of milk 
and purified, casein appears as a yellowish, translucent 
solid, not unlike horn ; in water this is ordinarily in- 
soluble, but in weak alkaline solutions it readily dis- 
solves. These facts will be of service to us in our sub- 
sequent examination of cheese as food. Casein is 
found in small quantities in certain vegetables, especi- 
ally in the leguminos?e — a family of plants, including 
peas and beans. If such seeds be finely ground and 
then treated with water, the casein passes into solution, 
and may be precipitated as a coagulum by the addition 
of acid. Dried peas and beans will yield 20 per cent, 
of their weight of vegetable casein. The Chinese 
manufacture from peas a good article of vegetable 
cheese, which is almost indistinguishable by chemical 

means from milk 
cheese. 

Gluten is a tough, 
elastic substance, 
present in flour, and 
imparting to dough 
its property of sticki- 
ness. It may be pre- 
pared by kneading 
flour with water on 
a fine sieve, after the 
manner indicated by 
Pig g^ figures?. The liquid 

Separating the gluten of flour. soon becomes milky 

from the starch granules that are washed from the 




244 DOMESTIC SCIENCE. 

dough ; the gluey mass remaining is a mixture of sub - 
stances, containing considerable quantities of vegetable 
fibrin and of vegetable casein, and about 20 per cent, 
of pure gluten. In a dried state, gluten is a horn-like, 
semi-transparent solid, insoluble in cold water ; slowly 
and but feebly soluble in hot water ; readily soluble in 
acetic acid (strong vinegar) and in dilute alkalies. 

Before leaving the albuminoids it will be well to con- 
sider some characteristics of the group. As already 
stated, they all contain a considerable quantity of 
nitrogen. Then further, they all possess the peculiar 
property of coagulation, though under different condi- 
tions ; thus, heat coagulates albumen, acid or rennet 
is needed to curdle casein ; blood "fibrin coagulates 
spontaneously. All albuminoids are readily decom- 
posable by heat, with evolution of an odor like that of 
burning horn. Under influences of moisture and 
warmth, albuminoids undergo a destructive change, 
known as putrefaction, in which process the albumi- 
noid matter becomes partially liquified, and gives off 
certain gases of disgusting odor. Albuminous matters 
have the power of acting as chemical ferments, so that 
if a small quantity of such in a decomposing state be 
placed with fresh material of the same kind, putrefac- 
tive changes are speedily excited throughout the whole 
mass. A bit of sour gluten introduced to dough soon 
'' leavens the whole." 



VEGETABLE FOODS AND THEIR COOKERY. 245 



CHAPTER 30. 

VEGETABLE FOODS AND THEIR COOKERY. 

HAVING considered the chief ingredients of ordinary 
foods, it will 'be profitable now to devote some 
attention to the food stuffs that supply these sub- 
stances. All of our common food materials are mix- 
tures of several of the alimentary substances already 
referred to ; it is common, therefore, to speak of 
ordinary foods as "compound aliments." Let us first 
consider the chief foods derived from the vegetable 
kingdom. 

1. TUBERS, BULBS, AND ROOTS. 

Potatoes cannot properly be classed as roots ; they have 
buds, (eyes), and rudimentary leaves (the little scales 
behind the buds), which no true roots possess ; they 
are to be regarded as enlarged underground stems, to 
which the common name tubers has been applied. Po- 
tatoes are very extensively used as articles of food, 
though as regards their chemical composition, they are 
deficient in nutritive elements. On the average, 
potatoes contain from 76 to 80 per cent, of water ; and 
of the remaining 20 or 24 per cent, dried matter, but 
a very small proportion is nitrogenous. In this re- 
spect the potato is even inferior to rice, which has long 
been regarded as one of the least nitrogenous of or- 
dinary foods. Prof. Johnston's analyses show the 



246 DOMESTIC SCIENCE. 

following relative composition of potatoes and ricCy 
only the dried substances being considered in either 



case : 





Potato 
per cent. 


Rice 
per cent, 


Gluten 


5 


9 


Starch, sugar, and gum 


81 


89 


Fat ... 


1 


0.5 


Mineral salts 


4 


0.5 



As a basis for farther comparison, it should be remem- 
bered that the dried potato substance contains not 
more than 8 per cent, nitrogenous compounds of any 
sort, whereas turnips contain 9.25 per cent, and 
mangel wurtzel 15.5 per cent, nitrogenous matter. 

The mineral substance or ash of potato tubers is very 
rich in potash, and contains a considerable proportion 
of other mineral compounds so essential in foods ; but 
much of this valuable material is removed by the or- 
dinary methods of cooking. The practice of peeling 
potatoes, and then immersing them in water, results 
in the washing away of many of their mineral salts. 
A potato contains within itself sufficient water for its 
perfect cooking ; and here we must pause long enough 
to inform ourselves of the chief differences between 
raw and cooked potatoes. Figure 85, upper left hand 
sketch, represents an enlarged view of a thin slice 
of potato tuber, showing the cells with their contents 
of starch granules ; and figure 84 a, shows the starch 
particles separated and more highly magnified. 

It will be remembered as a property of starch that 
the substance is insoluble in cold water ; but that 
it may be made to absorb a considerable amount of 
hot water. In cooking a potato, its starch granules 



VEGETABLE FOODS AND TSEIR COOKERY. 



247 




Fig. 88. 
Bursting starch granule. 



absorb water and burst ; a single grain presenting 
such appearance as shown in figure 88. 

As a result of heating pre- 
pared starch in water, a gelati- 
nous mixture is produced ; this 
condition is prevented in the 
case of the potato ; because 
the starch grains within the 
tuber are protected by stout 
cell walls, and the albumen of the potato coagulates 
through the heating process and thus still further pro- 
tects the starch. The starch of mature potatoes, when 
heated absorbs nearly all their contained water, and 
thus the tubers become dry and mealy ; young potatoes, 
when heated, and indeed all kinds, if cooked in a 
superabundance of water, become waxy because a 
considerable amount of water remains unabsorbed. 
From the standpoint of economy and wholesomeness, 
the best methods of cooking potatoes are roasting and 
steaming ; by either process the contained juices are 
raised to the cooking temperature, and are absorbed by 
the swelling starch particles. If "boiled" * at all, 
the least injurious way is to cook them with their skins 
still in place, leaving the peeling for a subsequent op- 



* It is a common but still a grossly improper practice to speak of 
things that have been kept for a time in boiling water, as being 
"boiled." Only liquids can boil, and in boiling they are converted into 
vapor ; thus water boils to steam ; alcohol m boiling produces alcohol 
vapor ; iron may be boiled, but it must first be melted to the liquid 
state ; then, if sufficiently heated, the molten metal may be converted 
into vapor of iron . Potatoes cooked in water are not boiled, any more 
than is tlie iron of the cooking vessel "boiled." The water boils, how- 
ever, and the effect of the boiling temperature is to produce within the 
potato the desired changes of cookery. 



248 DOMESTIC SCIENCE. 

eration. lu some parts of Ireland, the people depend 
largely upon potatoes for their support. And among 
them, experience has taught the ruinous waste of peel- 
ing potatoes before cooking. A potato diet is at best 
a very poor one, and a person subjected to it has to 
devour immense quantities of the vegetable to obtain 
the nutriment requisite for the support of the body. 
According to Smith, 2.5 pounds of potatoes are 
required to furnish the amount of carbon ordinarily 
contained in one pound of bread; and 3.3 pounds of 
potatoes contain more nitrogen than is contained in a 
pound of bread. AYilliams states that a pound of oat- 
meal is worth 6 pounds of potatoes, as regards the 
contained nitrogenous matter. * 

Potatoes serve an admirable purpose in diluting the 
fare of persons who are prone to excess in the use of 
over -stimulating and extra -nourishing food. 

Onions as used for food are thickened parts of the 
stems of the plant, and are botanically called bulbs. 
The onion is rich in nitrogenous matter, and is cor- 

* "My own observations in Ireland have convinced me of the wisdom 
of William Covbett's denunciation of the potato as a staple article of 
food. The bulk that has to be eaten, and is eaten, in order to sustain 
life, converts the potato eater into a mere assimulating machine dur- 
ing a large part of the day, and renders him unfit for any kind of 
mental or bodily exertion. * * * xhe effect of potato feed- 
ing may be studied by watching the work of a potato -fed Irish mower 
or reaper, who comes across to work upon an English farm where the 
harvesters are fed in the farm house, and the supply of beer is not 
excessive. The improvement of his working power after two or 
three weeks of English feeding is comparable to that of a horse when 
fed upon corn beans and hay, after feeding for a year on grass only. 
My strictures on the potato do not apply to them as used in England, 
where the prevailing vice of our ordinary diet is that it is too carniv- 
orous. The potatoes we eat with our meat serve to dilute it, and 
supply the| farinaceous element in which flesli is deficient."— W. 
Mattieu Williams. 



VEGETABLE FOODS AND THEIR COOKERY. 249 

respondingly nutritious. Its strong odor is due to the 
presence of a peculiar sulphurized oil, commonly 
known as garlic oil. In Spain and Portugal onions 
are used as staple articles of diet. As a result of 
chemical analysis, Prof. Johnston states that the onion 
contains from 25 to 30 per cent, of gluten.* Onions 
possess valuable medicinal properties, and the moder- 
ate use of the bulbs, either cooked or raw, is generally 
beneficial. On most people the physiological effect of 
onions is of a soothing kind, and in many instances 
the effect is decidedl}' soporific. «► 

Turnips, carrots, parsnips, and beets are true roots. 
They are rich accumulations of plant nutriment, being 
indeed the treasure vaults in which the growing plants 
have stored their gathered wealth, for use during the 
second year of their growth. These plants are all bien- 
nials ; during the first season they do not blossom 
at all ; their energies are devoted to the absorption 
and storage of food material, which if the growth 
be uninterrupted, will be used by the plant during the 
second year's stages of flowering and seed bearing. 
Man avails himself of their labors by cultivating the 
plants till they have accumulated their wealth of food, 
which then he appropriates to his own use. 

All the roots named possess less dry substance 
than do potatoes, av eight for weight ; it will be remem- 



* "It ranks," says he, "in this respect with the nutritious pea and the 
gram of the East. It is not merely as a relish, therefore, that the 
wayfaring Spaniard eats his onion with his humble crust of bread, as 
he sits by the refreshing spring ; it is because experience has long 
proved, that, like the cheese of the English laborer, it helps to sustain 
his strength also, and adds—beyond what its bulk would suggest, to 
the amount of noui'ishment which his simple meal supplies." 



250 DOMESTIC SCIENCE. 

bered that potatoes contain on an average of 20 to 25 
per cent, solid matter, while according to the figures of 
Dr. Youmans, turnips contain about 10.5 per cent, 
solid matter; yellow turnips 13.5 per cent., mangel 
wurtzel 15.5 per cent., carrots 14.22 per cent., beets 
10.9 per cent., and parsnips 19.6 per cent. The nature 
of the solid contents, however, is such as to place the 
roots far above the potato as tissue -forming food. 
The nitrogenous ingredients of the dried mangel wurt- 
zel amount to nearly twice as much as do those of the 
dri#d potato. 

In cooking, roots undergo changes analogous to 
those already described in the case of potatoes ; — the 
contained starch granules absorb water, swell and 
burst ; the albumen coagulates and the lignin or 
woody fibre, which is present in all vegetable tissues, 
becomes softened. If cooked in water, much of the 
mineral matter will be removed ; steaming and 
roasting are far better processes. The skin should be 
undisturbed until after cooking. 

Radishes are true roots ; they are used mostly as 
salad, and as such are eaten raw. Their nutritive value 
is low. 

2. LEAVES AND LEAF STEMS. 

These are less extensively used as articles of human 
food than are most other parts of plants. The nutri- 
tive qualities of leaves are shown by their composition 
and by the fact that herbivorous animals, including 
even those of gigantic bulk, derive their chief support 
from leaves. 

Cabbage is among the commonest of leaf foods used 



VEGETABLE FOODS AND THEIR COOKERY. 251 

by man. The plant contains 90 per cent, water; the 
remaining 10 per cent, of solids is rich in nitrogenous 
matter, and contains a small proportion of sulphurized 
compounds. Cabbage, therefore, supplies the ingre- 
dients in which potatoes are deficient, and a union of 
the two vegetables is a good one, and with the addi- 
tion of a little fat, makes a mixture that is generally 
nutritive. 

Spinach, dandelion leaves, nettle tops, turnip leaves, 
and the fleshy stems of asparagus are often used as 
"greens." They are all nutritive and valuable foods. 
Lettuce, water cress, garden cress, young mustard 
plants and celery, furnish leaves and leaf- stalks for food, 
and such are largely used in the raw state as salads. 
Lettuce contains a milky juice which is possessed of 
narcotic properties. From the juice of the native 
plant lactucarium is prepared ; this is used in medicine 
as a substitute for opium. 

The use of salads as food is productive of good from 
the fact that raw plants, when eaten, supply the body 
with an abundance of mineral salts ; these ingredients 
are frequently deficient in cooked vegetables. The 
Welsh peasant, and the Swiss mountaineer would be 
unable to preserve bodily strength on their ordinary 
diet of cheese and bread, but for the addition of raw 
salads in abundance. In this connection it should be 
known that there are many valuable sources of food 
growing wild about our houses ; but these we are apt 
to call weeds, and to treat them with disdain. Com- 
paring the customs of different peoples we find a very 
wide range of salad plants in constant use.* 
* M. Vitmorin, President of the Botanical Society of France, in a 



252 DOMESTIC SCIENCE. 

3. FRUITS. 

Fruits are common articles of food. Most of them 
are of a pulpy consistency, and contain a large propor- 
tion of Avater, with varying amounts of sugar, vege- 
table acids and pectin or vegetable jelly ; there are 
also present peculiar aromatic substances which give to 
fruits their characteristic flavors. We know compara- 
tively little of the exact composition of fruits. Ex- 
perience has proved them to be pleasing and whole- 
some, and in moderate amounts they may profitably be 
introduced in any ordinary dietary. Fruits may be 
eaten raw or in the preserved form ; most kinds may 
also be dried and kept without decomposition for long 
periods. Dried fruits should be cooked in water ; in the 
process they will absorb large quantities of the liquid, 
and become once more pulpy and juiceful. 

4. SEEDS. 

In nutritive value seeds represent the richest of or- 
dinary plant products, being indeed the accumula- 
tions of food material which the plants have stored for 
their offspring. Leguminous seeds, or those that grow 

recent lecture on "Salads," In March, 1890, stated that the French 
people excel in the use of salad preparations. He laid stress upon the 
nutritive value of salads as sources of potash and other mineral salts, 
which are commonly eliminated in the process of cooking. Among the 
various plants that are used in salads in France, he enumerated the 
leaves of lettuce, corn-salad, common chickory, water cress, dande- 
lions, (used green, blanched and half blanched), capucin, endives, 
purslane, (used in small quantities only), salsify tops, (described as 
being of a pleasant nutty flavor^ wltloof or Brussels chickory, roots 
of celeriac, rampion and radish; the bulbs of stachys, the stalks of 
celery, the flowers of nasturtium, and yucca, the fruit of capsicum 
and tomato, and, in the south of France, rocket, picridium and Spanish 
onions. Various herbs are added to a French salad as flavors or 
garnishes, such as chervil, parsley, olives, shallot, and borage flowecs. 



VEGETABLE FOODS AND THEIR COOKERY. 253 

in pods, such as peas and beans, are among the most 

concentrated of vegetable foods. Analyses by Horsford 

and Krocker, show table peas to consist of : 

Per cent. 
Albumen and Casein . 28.02 

Starch . . . 38.81 

Gum . . . 28.50 

Skin . . . 7.65 

Ash . . . 3.18 

The nitrogenous element of peas and beans is 
mostly vegetable casein, which has already been spoken 
of as the basis of Chinese vegetable cheese. 



254 DOMESTIC SCIENCE. 



CHAPTER 31. 

VEGETABLE FOODS CONTINDED GRAINS AND BREAD. 

AMONG the most important of vegetable seeds used 
as food for man are the grains ; and of these, 
wheat, barley, rye, oats, buckwheat, and rice are the 
kinds most commonly employed. 

Wheat is the staple food stuff, its chief preparation, 
bread, has long been known as the "staff of life." 
The average composition of wheat may be represented 
as follows : — 

Water - - - 11 to 15 per cent. 

Gluten - - - 12 to 18 " 

Starch - - - 53 to 64 " 

Sugar - - - 7 to 8 " " 

Gum - - - 5 to 6 " " 

Bran - - - 1 to 3 " " 

These figures are the results of numerous published 
analyses of specimens from many different sources. 
When a thin section of a wheat grain, properly 
mounted is examined under the microscope, a very 
regular arrangement of its constituent parts is revealed. 
Figure 89 represents a portion of such a section ; a 
shows the coats of the seed ; b marks a row of cells 
which are rich in gluten ; c shows the interior cells 
containing starch granules. The bran consists of the 
parts marked a and b. 

The first process by which wheat is prepared for use 
as human food is one of crushing or grinding ; this 
is usually performed between stones or rollers. The 



GRAINS AND BREAD. 



255 




Fig. 89. 
Part section of wlieat grain. 



resulting powder is then sifted and bolted, for the 
purpose of separating the coarse and fine particles. 

The outer layers of 
the grain constitute 
the bran; this, as 
separated in milling, 
amounts to about 15 
per cent, of the 
gross weight of 
wheat, though great 
variation exists in 
both the quantity 
and the composition 
of bran from different kinds of wheat, owing to the 
varying degrees of readiness with which the husks 
separate from the inner matter of the grain : in some 
cases, the bran carries with it a considerable part of 
flour from within. Chemical analysis shows the bran 
to be richer in nutritive elements than is the interior 
flour ; it is plain then that much valuable substance is 
lost from grain by the separation of the bran. 

The question- as to the relative merits of sifted and 
of whole-meal flours has long been agitated. Certain 
it is that the superfine flours now in the market are 
sadly deficient in essential alimentary matters, which 
have been lost in the milling processes ; and the results 
of experiment and of experience indicate a preference 
for whole-meal flour, though such should be ground 
fine. It is known that the husk of wheat is liable to 
produce derangement of the digestive organs because 
of its coarse, irritating nature* and its comparative 
* "If the husk, which is demanded by the whole-meal agitators were 



256 DOMESTIC SCIENCE. 

insolubility. The sketch of bran section on page — 
shows that the nitrogenous parts of the bran are 
mostly located in the inner layers of the husk ; the 
outer layer of bran contains about 4.5 per cent, 
gluten; the inner parts show 18 per cent. It is there- 
fore possible by removing the outer layers only to in- 
crease the proportion of nutritive ingredients in the 
remaining meal, at the same time rendering the flour 
more readily digestible.* 

Flour is now obtainable of many degrees of fineness, 
with corresponding variations in color ; the finest and 
whitest contain much starch, while the coarse and 
darker varieties show a larger amount of gluten and 
of mineral salts. It is plain then that the darker 
flours excel the superfine grades in nutritive value ; 
and that whiteness in flour cannot be properly con- 
sidered an indication of superiority. 

The ash of wheat is particularly rich in phosphoric 
acid, and other mineral ingredients of great service 
within the body. 

When wheaten flour is well moistened, its particles 
cohere to form a soft tenacious dough. If made from 
the best of flours ; i. e. varieties rich in gluten, dough 

as digestible as the inner flour they would unquestionably be right; 
but it is easy to show that it is not, and that in some cases the passage 
of the undigested particles may produce mischievous irritation in the 
intestinal canal. My own opinion on this subject * * * * 
is that a middle course is the right one, viz., that bread should be made 
of moderately dressed or 'seconds' flour, rather than overdressed 
'firsts' or undressed 'thirds,'— i.e., unsifted whole-meal flour." 

Mattieli Williams. 
* "This removal of the outer fibrous coat involves a loss of about 2 
pounds in 100 pounds of grain. It may be accomplished by moistening 
the grain and rubbing it, or by the special process of milling known as 
decortication." Johxston. 



GRAINS AND BREAD. 



257 




Fig. 90. 

Y east, as seen through the 

microscope. 



is very elastic and ductile ; admitting of ready mold- 
ing and rolling into thin strips. 

Dough that consists only of flour mixed with water 
is poorly adapted for the making of bread, as when 
baked it becomes hard, dense and brittle. To produce 

the soft, porous, spongy 
bread, so justly esteemed as 
the basis of our foods, a 
quantity of yeast is com- 
monly incorporated with the 
dough. Ordinarily, yeast 
appears as a murky liquid, 
with a bitterish taste and an 
odor that is suggestive of 
beer. On standing, bakers' 
yeast usually deposits a heavy 
sediment, which consists mostly of potato pulp and 
other vegetable matters added in the making. The 
purest and best yeast is the brewer's "barm," which 
is developed in the beer vats during fermentation. 

As an aid to our understanding of the use of yeast 
a few experiments should be mad^. If a small 
quantity of yeast be put into fresh fruit juice or any 
saccharine solution, and the mixture be kept at a 
proper temperature, bubbles of gas are soon evolved, 
and alcohol is formed, while the sugar of the liquid 
disappears. These changes are included under the 
general name of fermentation. The gas referred to 
may be collected and tested ; it will prove itself to be 
carbon dioxide. 

Now let us examine a drop of yeast microscopi- 
cally. With a proper magnifying power, we shall 



258 DOMESTIC SCIENCE. 

find it to be a collection of small oval bodies, dis- 
tributed through a watery liquid (figure 90). If 
yeast be filtered so as'to separate the tiny bodies from 
the liquid, the latter does not excite fermentation in 
sweetened fluids ; the corpuscles then are essential to 
the eflflcacy of the yeast. If yeast be boiled, it loses 
its peculiar power of producing fermentative changes ; 
this seems to be for the same reason that cooked 
potatoes and peas have lost their power of germina- 
tion — the heat has destroyed the vitality of the organ- 
ism. If yeast be added to pure water, it does not 
develop because there is lack of food materials ; yeast 
so treated in reality starves to death. In a properly 
prepared solution, however, the yeast rapidly in- 
creases, so that if but a few drops of yeast be added 
the whole liquid will soon be swarming with yeast 
organisms. The vitality of yeast is suspended at a 
low temperature ; this renders possible the preparation 
and use of "compressed yeast" which consists of yeast 
cells, freed from an excess of water, and preserved on 
ice in carefully wrapped packages. These facts should 
convince us that.the yeast corpuscles are in reality liv- 
ing organisms ; like other living things they grow in 
size and increase in numbers : they need food for their 
development, they may be starved, or may be killed 
by temperature too high or too low. Careful observa- 
tions warrant the conclusion that the yeast organism is 
in fact a plant. It lives and breathes essentially as do 
other plants, though it possesses peculiar habits of its 
own. The carbon dioxide and alcohol already referred 
to as products of yeast fermentation are indeed the 
exhaled breath of the plant. 



GRAINS AND BREAD. 259 

Now we should be able to comprehend something of 
the action of yeast in dough. The yeast is placed in 
the flour, with proper admixture of food materials, — 
potato pulp, hops, sugar, etc. ; the whole is then kept 
at a moderate temperature till fermentation has began ; 
then the flour and yeast are mixed, and thoroughly 
kneaded, by which process the yeast cells are dis- 
tributed throughout the dough. Fermentation con- 
tinues within the dough : the yeast plants thrive under 
the favorable condition of good food and proper 
temperature ; and they exhale much carbon dioxide 
and alcohol vapor. These gaseous emanations by 
their buoyancy strive to escape from the dough, and 
in so doiug cause a puffing of the latter which results 
in a rising of the dough and the formation of a 
sponge. The dough is next to be molded and set in 
the oven ; there the gases expand under the influence 
of increased temperature ; much of the water present 
is converted into vapor, and adds to the buoyant effect ; 
as a result the bread "rises" and becomes still more 
porous and spongy. The dough is partially dried, 
and the walls around the pores become sufiiciently 
rigid to permanently retain their position and shape. 
When the temperature has risen sufiiciently, the yeast 
plants are killed and the fermentation is consequently 
stopped at the proper stage. The best temperature 
for bread baking is about 450° F. ; this heat would 
completely char dry flour* ; but from dough evapora- 
tion of the water takes place as the baking proceeds, 
and this renders latent much of the heat, and prevents 

* Some bakers test the temperature of the oven by throwing a little 
flour upon the floor. If this blackens at once the heat is satisfactory. 



260 DOMESTIC SCIENCE. 

a burning of the dough. Inside the loaf the tempera- 
ture seldom far exceeds that of boiling water. The 
outer parts of the loaf are more highly heated than 
are the inner ; in consequence a surrounding shell or 
crust is formed. In this crust much of the starch has 
been converted into dextrin ; or if the loaf has been 
highly browned, some caramel may have been formed. 
Dextrin it will be remembered, is soluble in water, and 
in some instances a glossy film of dextrin is found on 
the outside of the loaf. The crust possesses a slightly 
sweetish taste, and is more readily dissolved in the 
digestive fluids than is the crumb. 

Freshly baked or new bread is tenacious, soft and 
apparently moist ; if kept some days after baking, 
however, bread becomes hard, brittle and seemingly 
much drier. Boussingault showed that the difference 
between new and stale bread is not entirely due to the 
drying process ; in demonstrating this he kept a very 
stale loaf in a heated oven for an hour ; during the 
operation the bread lost a quantity of moisture, be- 
coming in reality drier, yet it came from the oven as a 
new loaf.* 

Numerous substitutes for yeast in bread making 
have been proposed ; most of these are chemical mix- 
tures, passing under the generic name of baking 
powders. The principle upon which such preparations 



* "He," (Boussingault) "found that during the six days, while be- 
coming stale, it only lost one per cent, of its weight by drying ; and 
that during the one hour in the oven it lost three and a half per cent, 
in becoming new, and apparently more moist. By using an air-tight 
case instead of an ordinary oven, he repeated the experiment several 
times in succession on the same piece of bread, making it alternately 
stale and new each time." Williams. 



GRAIiSfS AND BREAD. 261 

act to render dough spongy, may be illustrated by 
mixing a little baking soda with dilute hydrochloric 
acid. As soon as the substances come together a copi- 
ous evolution of carbon dioxide occurs ; if such a 
liberation of gas should take place within the dough, 
it would cause the desired puffing and lightening of 
the latter. A common preparation of the sort consists 
of sodium bicarbonate, and hydrochloric acid, in the 
proportion of one ounce of soda, to nine fluid drachms 
acid ; these to be mixed with eight pounds of flour. 
Another product of the reaction between the acid and 
the soda, is sodium chloride or common salt, and as 
this is developed within the dough, and is therefore 
distributed throughout the mass, no other addition of 
salt is necessary in the process. 

Many common baking powders contain ammonium 
carbonate, which substance decomposes when exposed 
to heat, and forms gaseous ammonia, carbon dioxide, 
and vapor of water. These gases expand within the 
dough and produce a porous mass. The use of am- 
monium compounds is objected to for hygienic reasons ; 
yet baking powders of this sort are in commoner use 
than is generally supposed ; and a person may daily 
purqhase of our city bakers fresh hot cakes and 
biscuits all strongly smelling of hartshorn. 

Alum baking powders are considered objectionable 
by most hygienists. It has been proved that constant 
doses of alum will surely prove of detriment to health ; 
though the quantity taken at a single eating of alum 
bread is small. The chief reason for adding alum to 
dough, is to secure an increased whiteness in the 
bread ; this object it accomplishes admirably, though 



262 DOMESTIC SCIENCE; 

the mode of its operation is not well utiderstood; 
The "rocky" used by British bakers consists, accord- 
ing to Tomlinson, of one part alum and three parts 
common salt. 

Attempts have been made to introduce aerated bread 
to popular favor. To prepare this kind of bread, 
dough is made without admixture of yeast or baking 
powder ; this is then inflated and puffed by having air 
or carbon dioxide forced into it under high pressure. 
Bread so prepared has a peculiar "flat" taste, not at 
all appreciated by most people. 

Next to wheat, barley and rye claim our attention as 
grain -foods. These are both allied in composition to 
wheat. The following analyses by Poggaile are il-. 
lustrative : — 





Barley. 


Rye. 




Per cent. 


Per cent. 


Water 


15.22 


15.53 


Albuminoids 


10.65 


8.79 


Starch, dextrin 


60.33 


65.53 


Fat 5. 


2.38- 


1.99 


Woody fibre 


8.78 


6.38 


Ash 


2.62 


1.77 



Barley, though rich in nitrogenous matter, is de- 
ficient in true gluten, and is therefore not adapted for 
making dough. Hulled barley is the grain after the 
removal of its husk ; and pearl barley consists of the 
inner parts of the kernel only. Kye contains more 
saccharine matter than does either wheat or barley. 
Its bran possesses an aromatic flavor, which is ap- 
preciated by many. The nitrogenous matter of rye 
is closely allied to casein ; it has been called soluble 
gluten. 

Maize or Indian corn is rich in fatty matter, though, 



GRAINS AND BREAD. 263 

on the whole, it is less nutritious than is wheat. Its 
nitrogenous ingredient is peculiar ; unlike true gluten 
it is not adhesive, and corn bread in consequence 
crumbles readily. Compare the following analysis (by 
Poggaile) with the other analytical data already cited. 
Yellow maize contains : 







Per cent. 


Water 


- 


13.47 


Nitrogenous matter 


- 


9,90 


Starch, dextrin, sugar - 


- 


64.53 


Fats 


- 


6.68 


Woody fibre and coloring matter 


3.97 


Ash 


- 


1.44 



Corn meal readily spoils ; this is due to the ease 
with which the fatty matter undergoes oxidation. 
Crushed corn divested of its outer skin is known as 
hominy. 

Oats are in some parts of the world more extensively 
used as food for men than in this country. In nutri- 
tive value, that is as a flesh producer, oat flour excels 
all other preparations of the kind. Oats are rich in 
oily matter. Meal from oats is used mostly in por- 
ridge or gruel, though oat cakes are esteemed by those 
who have learned to know their merits. The follow- 
ing table represents the composition of dry oats ; it will 
be observed that the nitrogenous matter has received 
the special name, avenin (from avena, meaning oat) : 







Per cent. 


Water 


- 


14.3 


Avenin ') 






Albumen . - 


- 


12.0 


Gluten 






Starch, sugar, gum 


- 


54.9 


Fat ' - 


- 


6.0 


Woody fibre 


- 


10.3 


Ash 


- 


3.0 



264 DOMESTIC SCIENCE. 

Buckwheat is highly nutritious, being in 'some re- 
spects almost equal to wheat. 

Rice differs from most other grains by being richer 
than they in starch, and more deficient in oil and nitro- 
genous matters. The albuminoids are not more than 
half as abundant as in oatmeal. Some samples of rice 
contain over 80 per cent, starch, though the average is 
lovrer. Johnston gives its composition as : 

Per cent. 

Water .... 14.5 

Fibrin .... 7.5 

Starch .... 76.0 

Fat 0.5 

Fibre .... 1.0 - 

Ash 0.5 

Sago, tapioca, arrowroot are all rich in starch; 
likewise they are easily digested, but are very incom- 
plete foods when eaten alone. Nitrogenous and fatty 
matters should be added to them. 



ANIMAL FOODS AND THEIR COOKERY. 265 



CHAPTER 32. 

ANIMAL FOODS AND THEIR COOKERY *, MEAT AND EGGS. 

A LL kinds of lean flesh are rich in nitrogenous in- 
il gredients, principally as myosin, fibrin and albumen. 
Fresh meats contain a very large proportion of water ; 
lean beef is nearly 80 per cent, water. All meats, even 
the leanest, contain a considerable proportion of fat, 
which during the life of the animal existed within the 
body as oils. The following analysis (by Schurtz) of 
pure l^an beef is instructive : 

Fer-cent. 

Fibrin and myosin - - - 15.0 

Albumen - - - - 4.3 

Extractive matters, soluble in water t.8 

"alcohol 1.3 

Phosphates . _ . . traces 

Fat - - - _ - 0.1 

Water . - . _ _ 77,5 

This may be taken as a type of lean meats generally, 
though considerable variation exists between meats from 
different animals. Veal and venison are generally 
deficient in fat ; pork on the other hand is excessively 
oily. As a rule, the flesh of wild animals contains but 
little fat, whereas domesticated animals, even if in 
poor bodily condition, contain much oily matter. The 
analysis quoted above is of pure lean muscle as free 
from fat as it was possible to procure the same ; ordi- 
narily, however, meat contains several per cent, of fat ; 
of dry meat substance, fully one -fourth is fat. The 
flesh of birds generally contains less fat than does meat 

10 



266 DOMteSTIC SCIKNCE. 

from quadrupeds, though some birds when kept in 
captivity may be artificially fattened. 

Fish of different kinds show varying contents of fat. 
The flesh of all fish is rich in albuminoids, and in 
mineral salts, especially phosphates; some kinds, how- 
ever, as trout, whiting, sole, and carp are comparatively 
poor in fats, while salmon, eels, and others are par- 
ticularly rich in oil. 

As a rule, meats and fish in a fresh state are readily 
digested ; among meats, veal and pork are comparative- 
ly difficult to digest. Cooking is productive of many 
great changes in the condition of meat. If meat be 
immersed in cold water, much of its albumen and 
many of its sapid juces and mineral salts will be wash- 
ed away, and little more than the juiceless myosin. will 
remain. If meat must be seethed (or as it is improper- 
ly said, "boiled") let it be done by immersing the 
flesh in boiling water at first ; the effect of this will be 
to harden the albumen in the superficial parts of the 
meat, and produce an outer protecting layer by which 
the inner juices will be retained. The cooking should 
then be completed at a lower temperature ; between 
160° F. and 165° F. is best; for it will be remembered 
that the heat of boiling water is effectual in hardening 
albumen into an indigestible mass.* To guard against 
undue heat, it is well to conduct the cooking of 
albumen in a steam -bath or water -bath. The essential 



* "It should be boiled only for a few minutes, and then kept for 
some time at a temperature from 158° to 165°. Meat is underdone 
or bloody when it has been heated throughout only to the temperature 
of coagulating albumen (140°) ; it is quite done or cooked when it has 
been heated through its whole mass to 158° or 165°, at which temper- 
ature the coloring matter of the blood coagulates." Youmans. 




ANIMAL FOODS AND THEIR COOKERY. 267 

features of the latter are represented in figure 91; a is 
an outer vessel, containing "water, into which the 
cooking-receptacle, 5, is fitted. The contents of h 

will not be raised to the full 
temperature of boiling water. 
^^ In the preparation of soups, 
however, an opposite course 
is indicated. In such a case 
it is desirable to extract the 
iTig. 91. meat juices and this is best 

Water bath. done by subjecting meat in a 

minced state, to the action of cold water, the resulting 
extract of meat may be afterward heated and flavored. 
The heating, however, should be carefully regulated, 
else the temperature may rise to the point of coagula- 
tion of the contained albumen, which will then separate 
in shreds or flakes, and the careful cook will be sure to 
remove these floating bits, and thus will be lost some 
very valuable material. Myosin or animal fibrin is 
practically insoluble in cold water ; it is therefore im- 
possible to extract it by maceration, and although treat- 
ment with cold water will remove most of the sapid 
constituents of the meat together with some gelatin 
and mineral salts, leaving only a fibrous residue which 
is almost tasteless, and if eaten alone, actually nause- 
ating, still the extract without the fibre is a very poor 
diet. Many sick people have been almost starved on a 
beef tea regimen.* All kinds of meat extracts of which 

* Dr. Martin says of beef tea "The flavoring matters malce it de- 
ceptively taste as if it were a strong solution of the whole meat, 
whereas it contains but a small proportion of the really nutritious 
parts, which are chiefly left behind m tasteless shrunken shreds when 
the liquid is poured off. Some things dissolved out of the meat make 



268 DOMESTIC SCIENCE. 

there are many now in the markets are deceptive as to 
their true nutritive value. 

Under the best conditions, seething is a poor mode 
of cooking meat, except in making stews, in which 
case the watery extract and the solid residue are eaten 
together. 

Roasting a properly conducted will produce far better 
results. In the roasting process, meat should be ex- 
posed at the begining to an intense heat, — the best 
effects are obtained from an initial temperature of 400° 
F, ; by such means the surface albumen is hardened, 
and an impervious layer is formed about the inner parts 
in which the juices are held. This temperature should 
be maintained for a short time — for small joints about 
one -sixth of the entire time required for complete 
roasting, — the heat should. then be reduced and the 
subsequent cooking allowed to proceed at 200° F. 
The gravy of roasted meat consists of melted fat and 
some juice that has found its way out of the joint. 

In baking meats, a vessel of water should be set in 
the oven that the heated air may be well supplied with 
liquid ; else as its capacity for moisture increases with 
the rising temperature it will absorb the fluid parts of 
the meat and produce a disagreeable dryness of the joint. 
By the old-time style of spit roasting, it was necessary 



beef tea a slight stimulant, but its really nutritive value is small, and 
it cannot be relied upon to keep up a sick person's strength for any 
length of time. Liebig's extract of meat is essentially but a concen- 
trated beef tea; from its stimulating effect it is often useful to persons 
in feeble health, but other food should be given with it. It contains 
all the flavoring matters of the meat, and its proper use is for making 
gravies and flavoring soups, the erroneousness of the common belief 
that it is a highly nutritious food cannot be too strongly insisted npon, 
as sick persons may be starved on it if ignorantly used." 



ANIMAL FOODS AND THEIR COOKERY. 269 

to constantly baste the meat by pouring melted fat 
over the surface, otherwise a deplorable loss of juice 
would have occurred. Such fish as is naturally poor 
in oil should be coated with grease during the cooking 
operation, to aid in the retention of its juices. 

Broiling or grilUiig is a common method of cooking 
small pieces of meat, such as steaks, chops, and cutlets. 
The meat should be exposed to the high heat of a 
bright and smokeless fire ; the result will be a rich, 
juicy morsel ; whereas slow cooking will produce a 
dried ill -flavored piece, alike unattractive to eye and 
palate. 

Frying^ among all common operations of cooking is 
perhaps the most objectionable. As ordinarily per- 
formed, the frying process consists of smearing a thin 
layer of fat on the bottom of a frying-pan, placing 
therein the thing to be cooked — say for example a piece 
of meat — and heating the whole over a fire. But one 
side will "be heated at a time, and though the under 
surface may be browned, the upper side remains un- 
cooked long enough to allow the escape of juices from 
within. Some fat will be absorbed by the meat, and 
the fibres becoming thus coated will resist the subse- 
quent action of the digestive fluids. The great mistake 
in ordinary frying lies in proceeding as if the cooking 
depended upon direct conduction of heat from the fire 
through the iron floor of the pan to the meat, the fat 
being regarded as useful only in preventing a sticking 
of the meat to the metal. The fat should be suflScient- 
ly abundant to envelop and surround the meat, as by 
such a method only can heat be communicated uniform- 
ly on all sides. Good cooks are now abandoning the 



270 



DOMESTIC SCIENCE. 



frying pan for the frying kettle ; an illustration of the 
latter device is here reproduced (after Gouffe). The 
vessel is a deep one ; a movable tray of coarse-mesh 
wire (shown here removed) rests within an inch or 
two of the bottom. Sufficient fat is placed within 
to completely cover this tray when the latter is in 





Fig. 92. 
Frying kettle. 

position. The fat is highly heated, and the thing to 
be cooked is then placed upon the wire support, com- 
pletely immersed in the oily bath. The effect of this 
method is to heat the object on all sides, and to retain 
most of its juices. Contrary to ordinary expectation, 
experiment shows that such a bath of fat may be used 
for fish, meats, vegetables, and fruits in succession, 
without communicating the flavor of one to the others. 
The employment of so large a quantity of fat is not as 
extravagant as would at flrst thought appear, as less is 



ANIMAL FOODS AND THEIR COOKERY. 271 

absorbed by this process than by the greased pan 
method- When necessary, the fat may be purified 
by removing its suspended particles as sediment or 
scum. 

£Jggs constitute an important item of animal food. 
Tliose of domestic fowls, ducks, geese, and turkeys 
are commonly used. An examination of an egg will 
show it to consist of shell, white, and yolk ; of these 
the shell is discarded from food, the other parts are 
eaten. The white of egg is almost pure albumen; 
the yolk consists mainly of water, albumen, and a 
peculiar oil, bright yellow in color and containing 
compounds of sulphur and phosphorus. This oil 
forms nearly two -thirds by weight of the perfectly dry 
yolk. The fat of the egg is concentrated in the yolk, 
the white being poorly supplied with oily matter. The 
composition of eggs will be understood from the follow- 
ing table (Johnston). 







White. 


Yolk. 


Whole egg, 






Per cent. 


Per cent. 


Per cent. 


Water 


- 


85 


51.5 


71.75 


Albumen - 


- 


12 


15 


14 


Fat, etc. - 


- 


2 


32 


13 


Phosphates, 


etc. 


1 


15 


1.25 



In cooking eggs it should be remembered that the 
albumen is completely coagulated at a temperature 
below 160° F. ; and any higher heat will harden the 
substance. The old time method of cooking eggs was 
to keep them in boiling water for three minutes ; ^^egg 
timers" were made on the principle of the hour glass ; 
as soon as the eggs were immersed the glass was 
turned, and when the sand had run its course the eggs 
were considered done. A better method consists in 



272 DOMESTIC SCIENCK. 

placing the eggs in water that is near the boiling 
temperature, allowing about a pint of water to each 
egg. The eggs will share the heat of the water and the 
temperature will be reduced to the required degree, 
and the cooking will proceed without danger of over- 
heating. The vessel containing the water and eggs 
should of course be set aside from the fire ; the eggs 
cannot become hard even by prolonged exposure to 
water below 160° F. 



ANIMAL FOODS CONTINUED. 



273 



M 



CHAPTER 33. 

ANIMAL FOODS CONTINUED; MILK, Bl TTEK, AND CHEESE. 

ILK constitutes the sole food of infants and of the 
young of many animals ; this fact is proof of its 
nutritive value. Chemically, milk consists of a large 
proportion of water in which is dissolved sugar, cas«in, 
and mineral salts, while oil or butter particles are sus- 
pended in the fluid. The following table represents 
the mean composition of milk from different sources : 





Cow. 


Goat. 


Ewe. 


Human 

Milk. 


Water . 


87.02 


86.80 


85.62 


88.90 


Casein (curd) 


4.48 


4.08 


4.50 


3.90 


Fat (butter) . 


3.13 


3.32 


4.20 


2.67 


Sugar of milk 


4.77 


5.28 


5.00 


4.36 


Saline matter 


.60 


.52 


.68 


.14 



A drop of milk when viewed through the micro- 
scope appears as a collection of many floating globules ; 

such a view is represented 
in figure 93. Milk, there- 
fore, is both a solution and 
an emulsion. New milk is 
slightly alkaline ; this prop- 
erty assists in keeping the 
fat globules in suspension. 
Oil and pure water may be 
agitated together, yet as soon 
as the liquids come to rest 
they separate ; but if the 
liquid be first rendered slightly alkaline, the oil by 




Fig. 93. 
Milk viewed through the micro- 
scope. 



274 DOMESTIC SCIENCE. 

shaking will become more finely divided, and part of 
it will be permanently distributed through the water. 
As milk sours it becomes less able to hold fat globules 
iu suspension. 

Milk is used in its raw state, though boiled milk 
is a constituent of many prepared dishes. In boiling 
milk its albumen coagulates and appears upon the 
surface as a scum ; this coagulum is impervious to 
steam, consequently vapor cannot readily rise from 
the heated liquid, and the milk "boils over" if the 
heat be continued. All milk of unassured wholesome - 
ness should be boiled before being used, as a precau- 
tion against the possible communication of disease 
germs. Many contagious diseases have been spread 
through the medium of impure milk. 

The fat globules of milk are lighter than the rest 
of the fluid ; consequently they rise and form upon the 
surface an oily layer, which is mingled with consider- 
able casein or cheesy matter, and constitutes the cream. 
Not all the cream so rises, considerable still remains in 
"skim milk." The larger globules of fat rise first, and 
the cream that first forms is richer than that which ap- 
pears subsequently ; the dairy custom of skimming 
milk twice is a good one, as thereby may be obtained 
a quantity of richer and better flavored cream. Fat 
globules cannot readily rise from great depths of liquid ; 
it is therefore customary to set milk in shallow pans 
till the cream has risen. 

Milk is a nutritious food, though it is not adapted as 
the sole aliment of adults. It is a common supposi- 
tion that milk is apt to produce troubles of indiges- 
tion ; yet children live upon it while their digestive 



ANIMAL FOODS CONTINUED. 275 

organs are still weak. Ill results are likely to follow 
the rapid drinking of large quantities of milk, because 
the liquid curdles in the stomach, and if it be unmixed 
with gastric juice its assimilation within the body will 
be long delayed. Milk should be drunk slowly ; it 
should be sipped only, so as to imitate in some degree 
the natural method of swallowing milk directly from 
the lacteal glands. If milk be used as a beverage, a 
corresponding diminution in other animal foods should 
be made, else the consumer may suffer from over-nu- 
trition. 

By churning, the fat globules of milk are brought to- 
gether to form butter. Most of the water, casein, and 
mineral salts remain in the butter -milk. As ordinar- 
ily made butter contains about 10 per cent, water, 2 
per cent, casein (or curd), milk-sugar, and salt, and 
about 88 per cent. fats. It possesses in addition to 
these certain aromatic compounds of butyric acid, to 
which the peculiar flavor of fresh butter is due. Infe- 
rior butters contain much water and salt. 

Many so-called ^'artificial butters" have of late years 
been manufactured under the names of margarine, oleo- 
margarine, and butterine. These substances consist of 
soft animal fats mingled with true butter. In the 
preparation of such, animal suets are minced, heated 
and pressed, so as to yield their softer portions in a 
liquid state ; this oily matter is then filtered, mixed 
with milk and churned. As a rule these adulterated 
butters are manufactured with care and cleanliness ; 
only good fats are used in the process, and both chemi- 
cally and physiologically such preparations are as 
wholesome and almost as nutritious as is true butter. 



276 DOMESTIC SCIENCE. 

It is no less a deception, however, to sell them under 
the name of butter. Instead of seeking by legislative 
enactment to forbid the manufacture and sale of imita- 
tion butters, it would seem wiser to enact laws requir- 
ing such products to be sold under their true names and 
at a fair price. The author has analyzed and practic- 
ally tested many artificial butters, and he is convinced 
that good oleomargarine is far preferable in flavor 
and wholesomeness to inferior butter ; yet he is none 
the less disgusted that he has had to pay butter prices 
for that which was not butter. 

Cheese may be regarded as the pressed and salted 
casein of milk. ]\Iilk may be curdled in many ways. 
If left to itself it undergoes the change spontaneously ; 
acid may be artificially added to produce curd ; but the 
best method of causing coagulation is by the addition 
of rennet, which consists of the salted stomach of a 
sucking calf or pig. As the casein coagulates it takes 
with it a considerable amount of fat, together with some 
sugar and water, leaving most of the water, sugar, and 
mineral compounds in the whey. In precipitating 
curd by acid, many mineral ingredients are lost in the 
whey, whereas by the use of rennet they are retained 
in the curd.* Cheese is sometimes made from cream ; 
such cheese is of a very oily nature and is prone to 
rapid decomposition. Cheese made from unskimmed 
milk is considered best ; though that made from skimmed 
milk is rich in casein, but deficient in fats. The fol- 



* "Casein that has not been treated with acids contains about 6 per 
cent, of phosphate of lime; more, consequently, than is contained in 
auy of the protein compounds we have hitherto considered." 

LehmanN 



ANIMAL FOODS CONTINUED. . 277 

lowing table (by Johnston) represents the relative com- 
position of whole milk and skimmed milk cheese : 





Cheddar, whole 


Skim milk 




milk cheese. 


cheese. 




Per cent. 


Per cent. 


Water 


36 


44 


Curd or casein - 


29 


45 


Milk fat - 


30.5 


6 


Salt and phosphates 


4.5 


5 



As a food, cheese is not generally appreciated ac- 
cording to its merits. It contains fully twice as much 
nutritive solid matter as does the best selected meats. 
Cheese is by many considered to be difficult of diges- 
tion and generally productive of ill results. Undoubt- 
edly if eaten in large quantity, in addition to other 
highly nutritive foods, the bad effects of excessive nu- 
trition will be manifested. Cheese should be used to 
supplant, not simply to supplement, other animal 
foods. By proper cooking, cheese may be rendered easy 
of digestion. Mr. Mattieu Williams, of London, has 
reported many trials upon the relative merits of raw 
and of cooked cheese. He says : "I may here mention 
that I have recently made some experiments on the dis- 
solving of cheese, by adding sufficient alkali (carbonate 
of potash) to neutralize the acid it contains, in order 
to convert the casein into its original soluble form as 
it existed in the milk, and have partially succeeded 
both with water and milk as solvents.'- 



278 DOMESTIC SCIENCfe. 



CHAPTER 34. 

SOME AUXILIARY FOODS; 

BiSSIDE the classes of true foods already referred tOj 
there are certain substances which are commonly 
used in diet, not for their nutritive worth, but to im- 
part attractive flavors to regular food. These are 
sometimes called condiments. 

Vinegar is one of the commonest of condiments. It 
is produced by the acetous fermentation of saccharine 
solutions and fruit juices, such as cider and wine. Its 
essential ingredient is acetic acid, of which ordinary 
vinegar contains about four per cent. Commercial 
vinegars vary greatly in strength, however; the so- 
called "proof" vinegar contains 4.6 percent, acetic 
acid. 

According to their source and mode of preparation, 
common vinegars are described as malt vinegar, spirit 
vinegar, cider vinegar, and wine vinegar. Aromatic 
vinegars are artificially flavored and perfumed. It is 
generally believed that small quantities of vinegar may 
aid digestion by increasing the solvent power of 
juices within the stomach. Many albuminoid matters 
are partially soluble in diluted acetic acid. 

Vinegar from fruit juices usually possesses a peculiar 
aroma indicative of its source: white vinegar is with- 
out aroma ; it is a simple mixture of acetic acid and 
water, and may be cheaply prepared by adding pure 
acetic acid to water to produce the required degree of 



SOME AUXILIARY FOODS. 279 

acidity. If the abseuce of color be an objection, a 
very rich tint may be imparted by adding a little cara- 
mel or burnt sugar. Occasionally vinegar is adulter- 
ated with sulphuric acid ; this is an injurious addition. 
A competent chemist will readily detect the presence 
of the poisonous acid in any sample. 

Pickles are prepared by treating various vegetable 
products with brine and vinegar. They are used 
solely as condiments. If eaten in large quantity, 
pickles will certainly prove of detriment to the body. 
Pickling operations should be conducted in vessels of 
porcelain, stoneware or glass only. 

Acetic acid will attack metallic vessels, and form 
poisonous salts. The bright tints so much admired in 
bottled pickles are frequently due to the deadly copper 
acetate, formed by the action of pickling fluids on cop- 
per or brass kettles used in the process. 

Lemon and lime juices are sometimes used as sub- 
stitutes for vinegar. When mixed with water, they 
form agreeable beverages. Both substances are rich in 
citric acid, sometimes containing as high as 30 grains 
of acid to the fluid ounce of juice. A moderate quan- 
tity of these substances is of decided benefit to the 
body ; they are of medicinal effect in counteracting any 
tendency to scorbutic diseases. By the use of lime 
juice, scurvy has been checked among Arctic naviga- 
tors who have been long confined to a salt meat diet. 

Many essential oils are used for flavoring purposes ; 
such are oil or essence of lemon, orange, vanilla, nut- 
meg, banana, pine apple, etc. In large doses all of 
these substances are active poisons, but the amount 
ordinarily employed is so very small that no serious 



280 DOMESTIC SCIENCE. 

result need be feared from their occasioiial use. Many 
of the essential oils are largely adulterated, however. 

Apices and other aromatic compounds are also in 
common use as condiments. Among such may be 
named pepper, black and red, mustard and cloves iu 
the plain state, or prepared in sauces, horse radish, and 
many other substances. Savory herbs may be advan- 
tageously substituted for more stimulating condiments ; 
thyme, parsley, sage, sweet majoram, and mint, are in 
common use. 

Salt, though in some sense a condiment, is still an 
essential ingredient of food.* It has received atten- 
tion in a former chapter. 

Danger attends the frequent eating of stimulating 
condiments ; the digestive organs may be so habituated 
to the presence of such substances, that plain food 
seems insipid. The general effect of highly seasoned 
food is to produce an irritation of the intestinal tract, 
with strongly marked nervous affections, t 

Many artificial drinks, may, with propriety, be 
classed under the title of auxilliary foods. All bever- 
ages other than water or milk, may be so regarded ; 
though we would best exclude from the list alcoholic 

* "Hard work and attendant good appetite re(iuire little else than 
common salt as a condiment, which should be plentifully used. It 
was said by Plutarch that hunger and salt were the only sauces known 
to the ancients, and the very word 'sauce,' is derived from the Latin 
word sulsus, 'salted.' "— McSherry. 

t Dr. Beaumont says: "Condiments, particularly those of the spicy 
kinds, are not essential to the process of digestion, in a healthy state of 
the system. They afford no nutrition. Though they may assist the 
action of a debilitated stomach for a time, their continual use never 
fails to produce a weakness of that organ. They affect it as alcohol or 
other stimulants do ;— the present relief afforded is at the expense of 
future suffering." 



SOME AUXILIARY FOODS. 281 

liquors of all kinds ; none of which, from a chemical 
or a physiological standpoint, can properly be classed 
as foods, except by reason of the small proportion of 
sugar and extractive matters which they contain. Al- 
cohol, though consisting of carbon, hydrogen, and oxy- 
gen, is not digested or assimilated within the body. 

Liebig, the noted chemist, declared that a bit of 
flour, which can be picked up upon the point a knife, 
contains more nutriment than two gallons of the best 
beer. 

Tea as ordinarily prepared is an infusion of the 
dried leaves of the tea plant, a small shrub which is 
grown mostly in China. Under cultivation, the plant 
is from three to six feet in height, and reaches maturity 
in two years ; it yields three crops of leaves per year. 
The first crop of the season furnishes the youngest, 
tenderest, and most fragrant leaves. The tea leaves 
are gathered by hand ; while fresh, they possess none 
of the fragrance of dried leaves. They are subjected 
to a complicated roasting in open vessels with frequent 
shaking and rolling ; by this process some water is 
expelled, the color of the leaves is changed, and their 
aromatic properties are developed. 

The difference between green and black tea is 
mainly dependent on the preparation, though some 
choice is indicated as to species best suited for one 
kind or the other. 

Chemical analysis shows tea to contain a volatile oil, 
theine, tannin, and gluten. 

The oil of tea is volatile, and strongly aromatic ; to 
jt is largely due the flavor of tea. The potent proper- 



282 DOMESTIC SCIENCE. 

ties of this substance are illustrated by the fact that 
a hundred pounds of leaves contain less than half a 
pound of the oil. Its effect upon the human system is 
shown in nervous disorders and in the separated state 
it is known to be a powerful poison. Tea drinkers, 
professional tea tasters, and especially packers of tea 
leaves, are subject to headaches, giddiness, and in 
severe cases even paralysis. Tliei7ie is a white, crys- 
talized solid which may be readily sublimed from dried 
tea leaves. It belongs to the chemical family of alka- 
loids, all of which are of a poisonous nature. In small 
doses, it stimulates the body, and to its action is due 
the deceptive feeling of increased strength to the habit- 
ual tea- drinker. Teas of medium quality contain from 
2 to 3 per cent., and exceptional samples have shown 
even 6 per cent, of the alkaloid. Tawmw is the astrin - 
gent principle of tea ; the substance is so named from 
its abundant occurrence in oak bark, which is used in 
tanning. Tannin and tannic acid produce inky infu- 
sions with water containing iron. It aids in produc- 
ing the stimulating effect which usually follows an 
indulgence in tea drinking. 

Gluten is present in tea to the extent of 20 to 25 per 
cent. As the substance is insoluble in water, it is not 
extracted in the infusion, but is lost in the dregs. 

The infusion of tea contains the soluble matter, 
including the tannin and volatile oil. If the steeping 
be done in a closed vessel, a very fragrant liquid 
results. The tannin is extracted after long steeping; 
the volatile oil, however, is expelled by prolonged 
heating; to procure at once a fragrant and strong in- 
fusioiij two lots of leaves should be steeped ; one for a 



SOiViE AtJXILlARt FOODS. 283 

few minutes only, the other for a longer time ; the two 
infusions should then be mixed. 

Coffee is an infusion of certain roasted seeds, the 
commonest being derived from the coffee tree. In a 
cultivated state this tree reaches a height of 6 to 10 
feet. The best seeds are very improperly called "coffee 
beans" and "coffee berries." The best quality is 
Mocha coffee, then follow Java coffee. East India 
coffee, Ceylon coffee and Brazilian coffee. Coffee 
seeds contain a volatile aromatic oil. This is present 
in so small quantity that 50,000 pounds of the coffee 
seeds would yield but one pound of the oil. Pay en 
says the oil could not be prepared and sold at a lower 
cost than $500 an ounce. Coffee seeds contain also 
glaten ; an alkaloid known as caffeine, now supposed 
to be identical with theine, and an astringent principle 
— -caff eo - tannic acid, analogous in properties to the 
corresponding ingredients of tea. 

Cocoa and chocolate are prepared from the cocoa 
seed, which is grown in South America, and the 
West Indies. These beans are particularly rich in 
fatty matter, to which is given the name "cocoa but- 
ter." This exists in the bean to the extent of over 
50 per cent. An alkaloid body is present in the beans ; 
this is called theobromin ; it is similar in properties to 
theine. The ground beans, sometimes mixed with 
sugar, and often fraudulently adulterated with starch 
and flour, etc., compose cocoa. If the product be 
flavor and seasoned, it is called chocolate. Cocoa and 
chocolate as prepared for the table, are not mere infu- 
sions, but rather in the nature of soups or gruels. All 
the nutriment of the solid therefore enters the body. 



284 DOMESTIC SCIENCE. 

All the prepared cocoas and chololates of the market 
are largely adulterated, * and the proportion of active 
ingredients introduced into the body by drinking the 
beverage is correspondingly diminished, and the in- 
dulgence is less .fraught with danger to the nervous 
organization of the body. The pure cocoa bean would 
exert stimulating and narcotic effects analogous to 
those resulting from the use of tea or coffee. 

The general effect of tea and coffee is to produce a 
stimulation of the nervous system, which is followed 
by a reactive depression. Long continued indulgences 
produce specific derangements to which the name "tea 
disease" has been applied. The custom among stu- 
dents of drinking coffee to keep them awake is 
suicidal. The system may be habituated to these as 
to any other stimulants, and when their use is discon- 
tinued serious discomfort results, t The habit is an 
enslaving one ; it makes man dependent on drugs for 



* The common adulterants of cocoa are often of a disgusting kind. 
The following is on the authority of Dr. Yumas who quotes from Nor- 
mandy. "1 have known cocoa powder made out of potato starch 
moistened with a decoction of cocoa-nut shells and sweetened with 
molasses ; chocolate made of the same material with the addition of 
tallow and ochre— a coarse paint. I have also met with chocolate in 
which brick dust or red ochre had been introduced to the extent of 12 
per cent." 

t "I recommend tea drinkers who desire to practically investigate 
the subject for themselves, to repeat the experiment I have made. 
After establishing the habit of taking tea at a particular hour, sud- 
denly relinquish it altogether. The result will be more or less un- 
pleasant; in some cases seriously so. My symptoms were a dull head- 
ache and intellectual sluggishness during the remainder of the day,— 
and if compelled to do any brain work, such as lecturing or writing, I 
did it badly. This, as I have already said, is the diseased condition 
induced by the habit. These symptoms vary with the amount of the 
customary indulgence, and the temperament of the individual."— 
Williams. 



SOME AUXILIARY FOODS. 285 

the exercise of his powers. Such habits are cords that 
bind mind and body in the exercise of their functions. 
The substances are potent medicines, and should be 
used with great wisdom. As daily indulgences they 
are not good for the body. 



286 DOMESTIC SCIENCE. 

CHAPTER 35. 

PRESERVATION OF FOOD STUFFS. 

ALL organic matters, to which class of substances 
our ordinary food stuffs belong, easily undergo 
decay. In this process certain of their elements are 
separated and then recombined in different proportions, 
producing compounds entirely unlike the original. 
Were it not for such ability of ready change, easy diges- 
tion of foods would be impossible, for this bodily pro- 
cess is one of change, in which new and strange pro- 
ducts are formed from the elements of food. With ni- 
trogenous compounds, the process of decomposition is 
known as putrefaction, and the products are usually 
disgusting to our senses. Decomposition and recom- 
posititiou changes of a less disagreeable nature, espec- 
ially such as occur in carbohydrates, are spoken of as 
fermentation. 

From very early times, man has striven to devise 
a method of preserving food by artificial means, so as 
-3 ^ i>^ <«.> to prevent these destructive changes. 

^ -s»o t <rs^ Let US first consider the nature of 

\" ." ^^% the decomposition process. When- 
,, ^ ^ y ever putrefaction of organic matter 

cm{§ ^^■^~' '^^ ^^ progress, the microscope re- 
^3^1^^^^^^ ^ veals within the substance the pres- 

^ ence of manv tinv forms of life, the 

Fig. 94, chief appearances of which are shown 

Bacteria. ju Figure 94. These tiny organ- 

isms have received the generic name of bacteria^ from 
a word meaning little rod or staff, and so applied be- 



PRESERVATION OF FOOD STUFFS. 287 

cause of the rod -like shape of the typical and com- 
monest form. The bacteria are known to belong to 
the kingdom of plants, and to the order of fungi ; they 
are, therefore, closely related to the yeast plant. 

A discussion has been indulged in among scientists, 
as to whether the presence of bacteria is the cause of 
decay, or decay the cause of bacteria being present ; 
we may leave the contestants to their own dispute and 
accept these facts, which both parties admit, that spon- 
taneous decay of organic matter is not known to occur 
until such organisms are present ; and, farther, that 
any method by which these organisms may be excluded 
or killed, will arrest or prevent putrefaction. 

A time-honored mode of preserving food substances 
is by freezing . It is well known that decay is more 
rapid in summer than in winter ; and this is perhaps 
due to the inactivity of bacteria at low temperatures. 
Perishable foods are usually kept on ice, refrigerators 
or ice boxes are now in common use for this purpose. 
Carcases of sheep and cattle are shipped in a frozen 
state from Australia and New Zealand to Europe, and 
the meat is eaten months after the time of death. Chem- 
ical analysis fails to reveal any objectionable properties 
in frozen meat, though practical experience demon- 
strates a great superiority of fresh flesh over preserved 
meats of any kind. 

Food stuffs are often preserved by hermetic sealing 
in cases. Meats are usually kept in cans ; fruits in 
bottles. In canning or bottling, the material is placed 
in the vessels and heated to the boiling point of water, 
in order to destroy the bacteria present ; the cans are 
then securely closed by having the tops soldered in 



288 DOMESTIC SCIENCK. 

place, and the bottles are closed by tightly fitting 
screw-lids. If the process be thorough, all bacterial 
organisms there present being killed, and others pre- 
vented from gaining access, no decomposition will take 
place. It has long been supposed that this preserva- 
tive effect is due to the exclusion of air, and that 
oxygen is the chief agent of putrefactive changes. It 
is true that the chemical changes of decay are processes 
of oxidation ; but that spontaneous decomposition is 
closely associated with bacterial life is equally certain. 
Prof. Tyndal and other eminent experimenters have 
conclusively shown that air tJioroughly cleayised from 
all germs of life may be freely admitted to perishable 
articles without causing decomposition. Air may be 
so cleansed in many ways, by being passed through 
a heated tube, thus burning to death the bacterial or- 
ganisms ; or by thoroughly washing by means of a spray 
of water, by which the organisms will be stopped ; or by 
being strained through a thick filter of cotton fibre. 
The writer can personally vouch for the reliability of 
the method of securing bottled fruits by tying tightly a 
thick layer of cotton batting over the mouth in place of 
the ordinary screw top. Through this fibrous cap the 
air can make its way with ease, but all solid particles, 
both living and dead, will be stopped. As bottles and 
cans of fruit are ordinarily sealed at the boiling tem- 
perature, there is a shrinkage of the contents as cool- 
ing proceeds, and a consequent tendency of the outer 
air to force an entrance. This outside pressure will 
depress the top of a well -sealed can ; but if fermenta- 
tive changes have taken place within, the accumulation 
of gas will cause a bulging of the top and bottom. 



PRESERVATION OF FOOD STUFFS. 289 

Beware of such over-filled cans, their contents are 
spoiled. 

The use of canned foods is fraught with danger from 
the fact that poisonous compounds are often formed by 
the action of the juices upon the metal of the can ; 
and such are sometimes derived from the solder and 
the soldering fluids. Tinned ware is often 

adulterated with lead; and cases of lead -poisoning 
are not infrequent among the users of canned goods. 
Zinc chloride (butter of zinc) is largely used as a 
soldering medium, and some of this poisonous sub- 
stance occasionally becomes mixed with the food con- 
tents of the can. 

Drying, an effectual method of preservation, admits 
of application to meats, vegetables, and fruits. The 
appearance indicates, and analysis proves, that food- 
stuffs all contain a large proportion of water. The 
bacteria of putrefaction cannot thrive unless freely 
supplied with water ; dryness renders them inert, 
and is an effectual hindrance to their destructive 
growth. Succulent vegetables and fruits by drying 
lose many of their flavoring ingredients, though but 
little real nutriment is sacrificed. To be prepared for 
the table, dried foods should be soaked in water, that 
they may absorb the proportion of liquid formerly lost. 

Many chemical antiseptics are known. Common salt 
is one of the most eflicient among these. If dry salt* 
be added to fresh meat, a brine soon forms ; this is due 
to the strong attraction which salt possesses for water, 
whereby it robs the moat of its juices ; the meat in 
itself becomes in reality dryer, though outwardly it 
appears in the very opposite condition. The chief 



290 DOMESTIC SCIENCE. 

reason that salted meat does not putrefy is due mainly 
to the abstraction of water ; though salt itself in large 
quantities is fatal to bacterial existence. 

Much of the mineral matter of the meat is dissolved 
with the juices in the brine during the salting process ; 
and meat so preserved is consequently deficient in 
these essentials. The eating of salted flesh, if long 
continued, may produce serious derangement of health. 
Scurvy is a common disease among sailors who are fed 
on such meat. Sugar is also a valuable antiseptic ; it 
is used in pickling and curing meats, but more 
especially in the preserving of fruits, by dissolving 
in the fruit juices, and thus converting them into 
syrups, sugar exercises a drying effect upon the tis- 
sues, and so retards decomposition ; and farther, the 
mere presence of sugar in abundance prevents the 
growth of bacteria. In dilute syrups, fermentation 
may be set up, unless the containing vessels are 
secured by hermetic sealing against the possible 
entrance of germ -laden -air, as is done in the case of 
bottled and canned fruits. 

Alcohol preserves organic tissues immersed in it, 
by uniting with the constituent water, and thus dry- 
ing the solid parts. A little strong alcohol poured 
upon the white of egg converts the albumen into a 
tough, leathery mass, and analysis shows this to be 
very deficient in water as compared with the liquid 
white; and by the process the alcohol is correspond - 
iugly diluted. Alcohol would exert a similar effect 
upon bacterial organisms that may find entrance to it, 
and thus it tends to prevent putrefactive changes. 
Vinegar checks decomposition of organic matter. Its 



FKESERVATTON OF FOOD STUFFS. 291 

general properties and uses have been alread}^ dwelt 
upon. 

Fish and meats are sometimes preserved in oil. 
This medium prevents the access of air to the im- 
mersed substances, and thus effectually guards against 
the entrance of germs of decomposition. 

Creosote is a powerful antiseptic ; a very weak solu- 
tion of the substance, if poured upon meat, will prevent 
decomposition of the latter even in the hottest 
weather. Creosote is the chief of the irritating con- 
stituents of smoke, and the efficacy of smoke-drying 
as a means of preservation is mostly due to the influ- 
ence of this substance. The amount of creosote nec- 
essary for preservation is extremely small, else great 
danger would attend its use, for the substance is a 
strong poison. 

Various preparations of boric acid are now used as 
antiseptics ; principally for preserving meats. The 
acid is introduced into the circulatory system of ani- 
mals before death so that the flowing blood may dis- 
tribute the material throughout the body.* The 

* Mattieu Williams thus describes the process and illustrates its 
eflBcacy: "The animal is rendered insensible, either by a stunning 
blow, or by an angesthetic, with the heart still beating. A vein, usu- 
ally the jugular, is opened, and a small quantity of blood let out. 
Then a corresponding quantity of a solution of boric acid raised to 
blood heat is made to flow into the vein from a vessel raised to a suit- 
able height above it. The action of the heart carries this through all 
the capillary vessels into every part of the body of the animal. . . , 
After the completion of this inoculation, the animal is bled to death in 
the usual manner. From three to four ounces of boric acid is sufficient 
for a sheep of average weight, and much of this comes away, with the 
final bleeding. On April 2, 1884, 1 made a hearty meal on the roasted, 
boiled, and stewed flesh of a sheep that was killed on February 8, the 
carcass being in the meantime in the basement of the Society of Arts. 
It was perfectly fresh, and without any perceptible flavor of the boric 
acid; very tender and full flavored as fresh meat." 



292 DOMESTIC SCIENCE. 

so-called "glacialine," now sold in packages and war- 
ranted to be a safe preservative, consists mainly of 
borax. A small amount of borax added to milk 
hinders fermentation and thus prevents for a time the 
souring of the liquid. 

Salicylic acid is growing in favor as a pre^^ervative 
of fruits and vegetables. The use of this has been 
proved by experience to be detrimental. The substance 
is a potent medicine, and when used continuously or 
in large quantity it is a poison. 

But for the very small quantities of antiseptic chem- 
icals necessary to produce the desired effect, great dan- 
ger would attend their use, for none of them are of 
themselves conducive to health. Eggs may be pre- 
served by varnishing the porous shells, so as to pre- 
vent the entrance of air. Dr. Youmans kept eggs 
in good condition for upwards of a year, by packing 
them in salt, small ends downward ; after that time 
they had lost nearly half their weight, but had not 
putrefied ; the interior of the egg, however, had become 
thick and shrunken. By coating the exterior with an 
impervious layer, the natural appearance of the inner 
parts may be preserved. This may be effected by 
dipping the eggs in a prepared solution of gum, or in 
melted fat or paraflSne. They should then be care- 
fully packed. Among recent methods, that of sub- 
jecting eggs to the action of sulphur dioxide, produced 
by the burning of sulphur, has produced good results. 



CLEANSING AGENTS. 293 



I=»jPlI^T I\7. 



CLEANSING AGENTS; AND POISONS AND THEIR 

ANTIDOTES. 



CHAPTER ae. 

CLEANSING AGENTS. 

'^PHE great solvent power possessed by water renders 
1 that liquid particularly useful as a cleansing medium, 
and the need of such a substance must be apparent to 
all. The furniture of the house, the utensils of the 
cook-room, the clothing of the body, and especially the 
skin itself, all call for periodical washings. Though 
water has appropriately been termed the "universal 
solvent," it possesses widely varying dissolving powers 
for different substances ; thus, a pinch of sugar or of 
salt will dissolve readily in a goblet of water, whereas 
a like quantity of sand may remain apparently undis- 
solved for an indefinite time, and for oily matters water 
exhibits positive repulsion. Yet very delicate chemi- 
cal analysis shows that some portion even of sand and 
of oil may be dissolved by water. 

As a rule, the solvent power of water is favoredby 
heat; the use of hot water for laundry and house 
cleansing is therefore indicated. A greatly increased 
solvent effect is produced by adding to the water certain 
chemical substances, prominent among which are the 



294 DOMESTIC SCIENCE. 

alkalies, potash, soda, and ammonia. From very early 
times, people have been in the habit of using wood ashes 
as an aid in washing clothes ; the effective ingredient 
of ashes so used is potassium carbonate (commonly 
called "potash," because prepared from the ashes of 
fires used in heating the cooking pots). A strong solu- 
tion of potash or of either of the other alkalies named 
possesses strongly corrosive powers ; only very dilute 
solutions can therefore be used for ordinary cleansing 
purposes, lest while removing the impurities the fabrics 
and objects themselves be injured. 

Experience has taught that it is better to restrain the 
corroding ardor of the alkalies by first combining them 
with fats so as to form Soa/ps. Ordinary fats and fixed 
oils consist each of two main ingredients, viz., glycer- 
ine and an acid, the latter commonly called a fatty 
acid. When heated with strong alkalies fats readily 
decompose, liberating their glycerine, while the fatty 
acids unite with the alkalies to form salts. Thus, fats 
containing olein, if heated with soda, would form 
glycerine and sodium oleate ; palmitin and stearin, the 
other two common fats, if similarly treated, would form 
sodium palmitate and sodium stearate ; if potash were 
used as the alkali, potassium oleate, palmitate, or stearate 
would be formed. These compounds of alkalies and 
fatty acids are soaps. Most soaps dissolve in water, 
producing very viscid solutions, which when agitated 
readily entangle air producing lathers. When used 
with hard waters, the alkali in the soap is exchanged 
for the lime or magnesia of the water, and thus soaps 
of lime or magnesia are formed ; these are insoluble 
in water, and rise to the surface as a scum. 



Cleansing agents * 295 

As soaps are among the chief of our common de- 
tergents, they will claim our attention. 

The chemical process of forming soap by decompos- 
ing fats through the agency of alkalies, is known as 
saponification ; it may be watched and studied at any 
soap-boiling establishment. The alkalies used in soap 
making are usually the hydrates of the metals ; these 
from their great corrosive powers are called caustic al- 
kalies. The soap in forming dissolves in the water 
present ; as the boiling continues much of the water 
is evaporated, the soap then separates from solution 
and rises to the surface ; this is removed, shaped in 
moulds, and allowed to partially dry before it is used. 
If caustic soda be used as the saponifying alkali, the 
soap may be more advantageously separated by adding 
common salt to the soap solution, whereby a strong 
briiie is formed, which coagulates the soap and causes 
its ready separation from the water. This "salting 
out' ' is not practicable in the making of potash soaps*, 
because the salt would decompose the potassium com- 
pound, forming a soda soap. 

There is great difference between the soaps made 
from these two common alkalies. Caustic potash is 
highly deliquescent ; that is to say, it possesses a great 
thirst for water, and so keeps the soaps formed by it 
in a partially liquid state ; from such soaps the glycer- 
ine cannot be well separated, this adds to the softness 
of the soap. Potash soaps are always soft soaps ; soda 
on the other hand forms ha7'd soaps. The consistency 
of the soap depends in some degree upon the fats used, 
though this condition is mostly influenced by the al- 
kali ; thus, hard tallow will produce a firmer soap than 



296 DOMESTIC SCIENCE. 

will olive oil ; yet an oil with soda will saponify to a 
comparatively hard soap, while solid tallow with potash 
will produce a semi -liquid soap. 

Among the common fatty bodies used in the pre- 
paration of soap may be named tallow, lard, palm oil, 
olive oil, cotton-seed oil, cocoa-nut oil, for hard soaps ; 
and fish oil, linseed oil, and marrow for soft soaps. 
Certain line grade toilet soaps are made of almond oil 
and spermaceti. Cocoa-nut oil is peculiar among fats, 
it being unaffected by weak alkalies, but readily sa- 
ponifiable by strong alkalies ; the resulting soap is sol- 
uble in brine, and, consequently, cannot be separated 
from water in the course of manufacture by " salting 
out.'' The oil is heated to a low temperature only, 
the lye is then stirred in, and saponification takes 
place at once. Cocoa-nut oil soap lathers with salt 
water ; it is therefore valuable for use at sea, and is 
known as marine soap. 

Common yellow sqaps contain resin ; other tints are 
usually produced by special coloring matters. The 
mottled appearance of some soaps is due to the pres- 
ence of insoluble metallic oxides, which are stirred into 
the soap as it hardens. Transparent soaps are produced 
by dissolving good hard soap in alcohol, then evapor- 
ating the solution till a clear jelly is obtained ; such 
soaps are usually pure and good, though they waste 
rapidly and are costly. True Castile soap is made 
from olive oil and soda ; the color is due to metallic 
oxides stirred into the mass. Many imitations of Cas- 
tile soap are now made from common fats. Glycerine 
soaps consist of a mixture of hard soap and glycerine ; 
the latter substance in small quantity only ; an excess 



CLEANSING AGENTS. 297 

of glycerine causes the soap to soften and gives but 
weak lathering properties, whereas a small amount of 
glycerine renders the lather tenacious and persistent. 

The poorer grades of soaps are sometimes made from 
very impure fats ; in such the microscope has revealed 
the presence of bits of bone, half- decayed areolar tis- 
sue, and even pus cells ; very serious results may follow 
the use of soaps of this sort, from the poisonous matter 
being absorbed through the skin. Such foul accom- 
paniments are, however, comparatively rare ; the chief 
inconvenience attending the use of poorly made soaps 
lies in the excess of free alkali which they contain. The 
smarting sensation following the use of such soaps on 
the skin is caused by the solvent action of the free al- 
kali ; relief may be found through the application of 
some very dilute acid, such as vinegar or lemon juice. 

Many soaps are largely adulterated, though most of 
the additions are comparatively harmless. The com- 
monest adulterants are fuller's earth, starch, and solu- 
ble silicates. Sodium silicate enables soap with which 
it is mixed to absorb a large quantity of water, and so 
greatly increases the weight; though, as the substance 
itself is a harmless detergent, the ill effects of its intro - 
duction are somewhat modified. 

With some soaps a quantity of fine sand or other hard 
insoluble powder is incorporated ; this by its abraiding 
action aids the cleansing operations. Most washing 
compounds are partially dried and finely divided soaps ; 
all such substances, as also common "washing pow- 
der," contain a great excess of alkali. "Washing 
fluids" are mere solutions of the caustic alkalies, soda 

and potash ; such are of advantage where very hard 

11 



298 DOMESTIC SCIENCE. 

waters are used, though such excess of alkali is gener- 
ally injurious to the skin, as also to most fabrics sub- 
mitted to their action. When soap dissolves in water 
some of its alkali is set free ; this combines in the wash- 
ing process with the oily matters of the dirt, and by 
saponifying such renders them miscible in water. 

Beside soap, and the free alkalies, potash and soda, 
which are the commonest detergents, aqua ammonia 
is also largely employed. This should be used only 
when greatly diluted with water. With oily matter it 
forms a soapy fluid, which is soluble in water ; hence the 
value of ammonia for removing grease from cloth, etc. 
Water containing a table-spoonful of ammonia to the 
gallon is an excellent wash for woodwork, and such a 
mixture is frequently applied to carpets for the pur- 
pose of brightening their colors. 

Spirits of turpentine, camphene (rectified turpentine) , 
and benzine (gasoline), are also eflBcient solvents for 
most fixed oils ; they are therefore useful in removing 
grease from clothing. 



feLEACHlN(>. 299 



CHAPTER 37. 

BLEACHING. 

IT is often found desirable to modify or to remove 
the natural colors of textile goods ; the process of 
whitening such fabrics is known as bleaching.* It 
has long been an art among men, they having learned 
its fundamental principles from observing certain 
operations in nature. Light and air are universal 
bleaching agents. 

The earliest processes of artificial bleaching consisted 
of exposing the colored fabrics to light and air. This 
was accomplished by spreading the goods on grass 
plats in the open sunshine, and by occasionally wetting 
them if dews or rain did not afford sufficient moisture. 
The explanation of the whitening process so con- 
ducted is simple as far as we understand it ; the 
oxygen of the air unites with the organic compounds 
constituting the coloring matters, thus changing their 
composition with consequent loss of their property of 
color. This operation is most applicable to cottons and 
linens. Under the best conditions sun -bleaching is a 
slow process ; in Holland where the art was most 
highly developed, the bleaching required for its com- 
pletion eight or nine months ; and oftentimes if the 
season were cold and wet the fabrics were injured by 
the continual exposure. The Dutch mode of pro- 

* The old English name for bleachers is "whitesters," or whitsters; 
it fully expresses the nature of their occupation. 



300 DOMESTIC SCIENCE. 

cedure in bleaching, consisted of treating the cloth for 
a week with caustic alkali or lye ; then came an im- 
mersion in buttermilk, and then the many months' 
exposure to sunlight and dew. The large space needed 
for the process gave to bleaching establishments the 
common name of "bleach- fields." 

Chemists have discovered several substances that 
possess strong bleaching powers. Of these, chlorine 
and sulphur dioxide are among the chief; and they are 
the ones that are best adapted for domestic applica- 
tion. 

Chlorine is a gas, yellowish green in color, and of 
penetrating, strongly suffocating odor. It is pos- 
sessed of remarkably strong chemical affinity for 
other elements, and will often decompose other com- 
pounds to form with the elements combinations of its 
own. Upon this property depends the value of chlor- 
ine as a bleaching agent, and, as will subsequently be 
seen, its efficacy as a disinfectant also. The tinted 
petal of a flower, a green leaf, or a piece of cloth dyed 
with vegetable colors may be readily whitened by exposure 
to the gas. To illustrate, placein a wide -mouth bottle a 
little chloride of lime; — this substance is a con- 
venient source of chlorine, and is commonly known 
as "bleaching powder ;" pour upon it a little dilute 
acid, — muriatic acid is best ; — then quickly cover the 
mouth of the jar with a plate of glass. The vessel 
will soon become filled with the green gas, — chlorine ; 
if you desire to test its odor, do so cautiously ; if in- 
haled in quantity it produces painful and injurious 
spasms ; suspend in the upper part of the vessel 
some bits of colored calico, and a colored flower, — all 



BLEACHING. 301 

of which must be moistened ; the colors disappear with 
magical quickness. 

Another pretty demonstration of the decolorizing 
action of chlorine consists in conducting the gas or 
pouring chlorine water into red ink, colored wine, in- 
fusion of red cabbage, or of indigo ; the tints almost 
instantly disappear. Printers' black ink is not so 
affected ; as its color is due to finely divided carbon 
(lampblack) which is not eager to form combinations 
with other elements. Dry substances are not whitened 
by chlorine and this fact is a key to an understanding 
of the bleaching process. Chlorine possesses a strong 
affinity for hydrogen, so strong indeed as to readily 
take the hydrogen from water, thus leaving the oxygen 
free ; this oxygen in its nascent or freshly liberated 
state eagerly unites with the organic coloring com- 
pounds, and, as was explained in the case of sun- 
bleaching, robs them of color. So that chlorine is not 
the true bleacher after all. Oxygen is the eflflcient 
color destroyer, the chlorine simply liberates the oxygen 
from its combination in water ; and thus there is great 
similarity between the processes of sun -bleaching and 
' 'chlorine -bleaching ;'' each is a result of oxidation. 

The bleaching operation may be carried too far ; for 
if after the coloring matters have been decomposed, 
chlorine be still allowed to decompose the water con- 
tained within the pores of the cloth, the energetic 
oxygen will attack the textile fibres themselves, and 
this will rot the fabrics. 

Exposure to gaseous chlorine is very apt to partially 
destroy the fabrics ; a more practical method, and the 
one most commonly adopted, consists in immersing 



302 DOMESTIC SCIENCE. 

the goods to be bleached in a sohition of chloride of 
lime ; they should be kept in the bath several hours, — 
sometimes days are required ; they are then to be re- 
moved, and if the whitening be not satisfactory they 
should be placed in a tub of acidified water ; the acid 
will liberate chlorine in quantity from the bleaching 
powder within the pores ; the acid treatment must be 
carefully watched, lest it result injuriously to the 
goods.* 

Colors bleached through the agency of chlorine can- 
not be restored, the pigment having been destroyed. 
Chlorine -bleaching is not applicable to straw, wool, or 
silk. For these, sulphur dioxide is employed as a 
whiteuer. This gas may be produced by burning 
sulphur in air; it is colorless, and produces an in- 
tensely irritating effect within the respiratory passages. 
Like chlorine it is soluble in water, and its solution 
possesses the essential properties of the gas. Sulphur 
dioxide is valuable both as a bleaching agent and as a 
disinfectant. Its bleaching powers may be prettily 
illustrated by holding a moist red rose over a bit of 
burning sulphur ; a burning match held beneath the 
flower is often effective in banishing the color. The 



* "A very elegant application of chlorine to bleaching purposes is 
made in the printing of bandanna handkerchiefs. The white spots 
which constitute their peculiarity are thus produced: First of all, 
the whole fabric is dyed of one uniform tint, and dried. Afterward, 
many layers of these handkerchiefs are pressed together between lead 
plates, perforated with holes conformable to the pattern which is de- 
sired to appear. Chlorine solution is now poured upon the upper 
plate, and finds access to the interior through the perforations. By 
reason of the great pressure upon the mass, the solution cannot, how - 
ever, extend laterally, further than the limit of the apertures, wljence it 
follows that the bleaching agent is localized to'the desired extent, and 
figures corresponding in shape and size to the perforations arebleached 
white upon a dark ground." Faraday. 



BLEACHING. 303 

process of sulphur -bleaching is conducted by moisten- 
ing the articles and suspending them in closed cham- 
bers in which sulphur is being burned. A large box 
or an inverted tub may be used as a bleaching chamber. 
The moistening of the goods is to aid the absorption 
of the gas. The coloring matters so bleached are not 
in reality destroyed ; the union between them and 
sulphur dioxide is an unstable one, and the colors are 
after a time restored in part. Flannels that have been 
bleached with sulphur dioxide often regain their color 
when washed with alkaline soaps. Certain chemicals 
— e.g. sulphuric acid, may promptly restore the color 
to articles so bleached. To illustrate this, prepare an 
infusion of logwood ; conduct into it gaseous sulphur 
dioxide, or pour into it an aqueous solution of the 
gas ; the color immediately disappears ; now add a 
little sulphuric acid ; the color is as promptly restored. 
Sulphur -bleaching is therefore only practiced in cases 
to which chlorine is not applicable, as in whitening 
silk, wool, and straw. 



304 DOMESTIC SCIENCE. 



CHAPTER 38. 

DISINFECTANTS. 

CERTAIN kinds of impurity cannot be removed from 
our dwellings by the ordinary methods of cleans- 
ing. The presence of dust in the house has been shown 
to be universal; the complex nature of the dust, con- 
sisting as it does of inorganic and organic matters, and 
even of living organisms, has been dwelt upon ; the 
close relationship between the progress of contagious 
diseases within the body and putrefaction without 
is now well understood. Following a consideration of 
these facts, the operation of disinfectants will be clear. 

A ''disinfectant" is a substance that destroys the 
eflu via of putrefaction, and the poison of contagion; 
yet the term, by a popular inaccuracy, is applied also 
to absorbents and deodorizers. Foul smells are usu- 
ally associated with poisonous properties ; the disagree- 
able odor seems to be a danger signal, affixed in wis- 
dom to many noxious matters. Fatalities from 
inhalation of the toxic coal gas, the nauseating hy- 
drogen sulphide, and the deadly prussic acid would be 
more frequent than they are but for the disgusting odor 
possessed by each of them. Substances that absorb 
ill -smelling matters, therefore, may be of value, yet 
they hold the offensive gases much as a sponge retains 
water, and they may again allow the escape of the foul 
matter. 

Charcoal and Lime are efficient absorbents of many 



DISINFECTANTS. 305 

foul gases. A solution of hydrogen sulphide shaken 
with fresh charcoal loses almost immediately its foul 
odor. Lime is less efficacious, yet it is valuable. The 
practice of whitewashing the walls of rooms, and es- 
pecially of cellars and such places, is very beneficial in 
sweetening the enclosed atmosphere ; though, as the 
lime soon loses this power, frequent renewal of the 
wall-wash is necessary. 

The merits of charcoal as an absorbent of gases are 
not generally recognized. It is used in water filters 
to arrest gaseous impurities ; organic filth of many 
kinds, even the bodies of dead animals if covered with 
a layer of freshly heated charcoal may undergo decom- 
position with no escape of foul effluvia ; tainted meat 
packed in charcoal loses its disagreeable smell ; the aii- 
of sick rooms may be greatly improved by placing 
therein charcoal in shallow pans. Finely divided char- 
coal is one of the most efficient and least harmful of 
powders for the teeth ; being soft it produces no in- 
jurious abrasions of the enamel, while its deodorizing 
action does much to sweeten the breath.* A small 
amount of pure charcoal swallowed immediately after 
onions will keep the breath free from disagreeable 
effluvia. A lump of clean charcoal in a cooking vessel 
with cabbage, onions, or other strong-smelling vege- 
tables, will prevent the escape of disagreeable odors. 
Roasted coffee is partially charred vegetable matter ; a 
few coffee seeds may be substituted for the lump of 

* Charcoal from wood is apt to be "gritty," such may be of injury 
if rubbed on the teeth. The best Ivind for the purpose named may 
be made by charring the crust of bread. Let the bottom crust of a loaf 
be removed in one piece, and this be completely charred before or over 
a glowing Are. It is then to be finely pulverized. 



306 DOMESTIC SCIENCE. 

charcoal in the cooking process just named. Bone 
black or animal charcoal has great affinity for the elements 
of vegetable colors, and is of great use as a decolorizer 
of syrups, etc., which are filtered through it. 

Certain substances are used as deodorizers, such as 
cascarilla, cologne, and other extracted perfumes, musk, 
fragrant spices, aromatic mixtures, burning coffee, and 
even smoldering paper and rags ; these, however, 
merely hide the bad odor by substituting a stronger 
one. Such substances are almost valueless as disinfect- 
ants.* Among common disinfectants the following 
are efficient ones : 

ChloriJie, in its pure state is a pale yellowish -green 
gas; intensely irritating if inhaled. Its chief proper- 
ties have been considered in connection with its use as 
a bleaching agent. Hydrogen sulphide, ammonia, and 
most other compounds formed by the putrefaction of 
organic matter are decomposed by the gas. If allowed 
to escape in closed rooms it will destroy or render inert 
most foul matters ; but it is likely to bleach the colors 
of furniture and drapery in the presence of moisture, 
and to corrode metals. Its most accessible source is 
Chloride of lime, or bleaching powder, which is pre- 
pared by saturating slaked lime with the gas. The 
powder contains about 30 per cent, available chlorine, 
which is set free very slowly by mere exposure ; but 

* "They are the only resources in rude and dirty times, against the 
offensive emanations from decaying animal and vegetable substances^ 
from undrained and untidy dwellings, from unclean clothes, from ill- 
washed skins, and ill-used stomachs. The scented handkerchief in 
these cases takes the place of the sponge and the shower bath ; the 
pastile hides the want of ventilation, the attar of roses seems to render 
the scavenger unnecessary, and a sprinkling of musk sets all other 
stenches and smells at defiance."— (Quoted). 



DISINFECTANTS. 307 

may be liberated very rapidly by the addition of an 
acid. The common attempt at disinfection by simply 
scattering lime chloride about the premises is a very 
ineffectual one ; the substance should be mixed with 
acid — hydrochloric acid, sulphuric acid, or even strong 
vinegar may be used. For disinfecting rooms, chlorine 
may be liberated by mixing 4 ounces of hydrochloric 
(muriatic) acid, previously diluted with three times its 
volume of water, and 1 pound of chloride of lime. 
Let the mixture be made in an earthen vessel ; the 
room should be immediately closed, and be kept un- 
opened for 24 hours. Another method of chlorine 
preparation consists in treating manganese dioxide 
(two parts by weight) with strong hydrochloric acid 
(three parts by weight). 

Sulphur dioxide is a colorless gas, entirely irrespir- 
able. It may be easily prepared by burning sulphur, 
and is an efficient disinfectant. It is in most respects 
best adapted among disinfectants for general use. Wet 
fabrics containing vegetable dyes are bleached, how- 
ever. To prepare and use the gas : set an iron pan on 
bricks in the middle of the floor ; as an additional pre- 
caution the bricks may be placed In a shallow tub con- 
taining water ; put the sulphur (roll brimstone is best 
adapted) in the pans, allowing at least two pounds for 
a room 10 feet square ; light by adding a small shovel- 
ful of glowing coals, or by pouring a table -spoonful of 
alcohol over the brimstone and applying a match. Let 
the room be closed, and remain so for 24 hours. Do 
not use chlorine and sulphur dioxide together ; they 
partially neutralize each other. 

Carbolic acid is prepared from coal tar ; it is a color- 



308 DOMESTIC SCIENCE. 

less crystalline solid, though by exposure to light and air 
it soon darkens. In an unmixed state it is very cor- 
rosive to organic substances, but being soluble in 
water it may be diluted to any degree. It is a sure de- 
stroyer of bacterial life if brought in contact with the 
organisms, and is also an antiseptic, acting in this re- 
spect much like creosote. A two per cent, solution of 
carbolic acid ; i. e. 2 parts acid diluted with 98 parts 
water, is suitable for most purposes. of disinfection. 
The odor of the acid is objectionable to many per- 
sons ; this may be somewhat modified by dissolving 
camphor in the acid before dilution. Many prepared 
disinfectants now offered for sale are mixtures of car- 
bolic acid and dilutents. Carbolic powders consist of 
the acid mixed with sawdust, lime, or clay. 

Thymol is another product of coal tar distillation. 
Its odor is agreeable, and as its disinfecting action is 
similar to that of carbolic acid, it is largely used as a 
substitute for the latter. It may be purchased in the 
solid state, or as spirits of thymol, consisting of 1 part 
thymol dissolved in 3 parts alcohol of 85 per cent, 
strength. To prepare for use, add one table-spoonful 
spirits of thymol to a half gallon of water. This solu- 
tion may be sprinkled about the apartment, even on 
carpets and draperies without serious detriment ; still 
further diluted, it may also be applied to the flesh as a 
wash, after exposure to contagion. Do not allow it to 
enter the^eyes. 

Copperas, iron sulphate, or green vitriol, may be 
purchased ; it is cheap. It exists as pale green crystals, 
and is very poisonous. Copperas is a good disinfect- 
ant; for use it should be dissolved in water, — 2 pounds 



DISINFECTANTS. ^OJ 



Of the crystals to a gallon of water. This solution 
may be improved by the addition of 2 ounces carbolic 
acid per gallon of fluid. AYhen required in large quan- 
tity, a basket containing fifty or sixty pounds of cop- 
peras may be suspended in a barrel of water ; the solu- 
tion soon becomes saturated. 

Lime and charcoal, though absorbents rather than 
disinfectants, occur as ingredients of many patented 
disinfectant preparations. Gypsum (lime sulphate) is 
mixed with carbolic acid, and used for disinfecting 

stables, etc. 

Corrosive sublimate or mercuric chloride, is a power- 
ful disinfectant, and acts by destroying the germs of 
decay. It readily coagulates albuminous matters. 
One part of the substance in 1000 parts of water forms 
a solution of suflacient strength to kill most bacteria. 
It is a deadly poison, and does not admit of general 
It should be employed only under skilled direc- 



use. 



tion. 

Certain Salts of zinc, especially the sulphate (white 
vitriol), and the chloride (butter of zinc), are good 
disinfectants. With albuminous matters they form in- 
soluble compounds, and act as absorbents for certain 
gases. The substances are poisons and must be used 
with care. A very good zinc disinfectant consists of 
zinc sulphate, 1 pound ; common salt, % pound ; and 
water, 4 gallons. Infected clothing, bedding, and the 
like may be immersed and boiled in the solution. 

Lead chloride is of service as a disinfectant, but 
must be used with care because of its poisonous nature. 
To prepare : Dissolve 1 drachm of lead nitrate m a 
quart of boiling water; dissolve also 4 drachms of 



310 DOMESTIC SCIENCE. 

common salt in a bucket of water, and mix the solu - 
tion. A copious precipitate of lead chloride will form, 
much of which will settle ; the superuataut fluid is ready 
for use. It may be sprinkled about the floor, or in 
drains and gutters. 

Heat is an important agent of disinfection. Cloth- 
ing, carpets, and such articles as admit of this treatment, 
should be boDed in water, or subjected to a dry heat 
in an oven at 250° to 300° F., for several hours. 
Woolen fabrics are injured by this. 

For house disinfection, abundance of fresh air. free 
access of light, and strict cleanliness are among the 
most valuable of disinfectants. Xo chemical preparation 
can take the place of the natural purifiers, air and light, 
and no cure of uncleanliness is equal to the prevention 
of such a state. 

Below is given a brief code of instructions for the 
management of contagious diseases, as authorized by 
the National Board of Health :* 

INSTRUCTIONS FOE DISINFECTION. 

Disinfection is the destruction of the poisons of in- 
fectious and contagious diseases. 

Deodorizers, or substances which destroy smells, are 
not necessarily disinfectants, and disinfectants do not 
necessarily have an odor. 

Disinfection cannot compensate for want of cleanli- 
ness nor of ventilation. 

I. Disinfectants to he employed. 

1. Roll sulphur (brimstone) for fumigation. 

* These instructions were prepared by a special committee of eminent 
scientific men. They are here quoted from Dr. Tracy's admirable 
little "Hand Book of Sanitary Information." 



DISINFECTANTS. 311 

2. Sulphate of iron (copperas) dissolved in water, 
in the proportion of one and a half pounds to the gal - 
Ion, for soil, sewers, etc. 

3. Sulphate of zinc and common salt dissolved to- 
gether in water, in the proportion of four ounces sul- 
phate and two ounces salt to the gallon, for clothing, 
bed linen, etc. 

II. — Hoiv to use disinfectants, 

1. In the sick room: The most available agents are 
fresh air, and cleanliness. The clothing, towels, bed- 
linen, etc., should, on removal from the patient, and 
before they are taken from the room, be placed in a pail 
or tub of the zinc solution, boiling if possible. All 
discharges should either be received in vessels contain- 
ing copperas solution, or when this is impracticable, 
should be immediately covered with copperas solution. 
All vessels used about the patient should be cleansed 
with the same solution. Unnecessary furniture, espec- 
ially that which is stuffed, carpets and hangings, should 
when possible be removed from the room at the onset, 
otherwise they should remain for subsequent fumigation 
and treatment. 

2. Fumigation with sulphur is the only practicable 
method for disinfecting the house. For this purpose 
the rooms to be disinfected must be vacated. Heavy 
clothing, blankets, bedding, and other articles which 
cannot be treated with zinc solution, should be opened 
and exposed during fumigation as directed below. 

4. Premises: Cellars, yards, stables, gutters, 
privies, cess-pools, water-closets, drains, sewers, etc., 



312 DOMESTIC SCIENCE. 

should be frequently and liberally treated with copperas 
solution. 

4. Body and bed-clothing, etc. It is best to burn all 
articles which have been in contact with persons sick 
with contagious or infectious diseases. Articles too 
valuable to be destroyed should be treated as follows : 
(a) Cotton, linen, flannels, blankets, etc., should be 
treated with the boiling -hot zinc solution, introduced 
piece by piece : secure thorough wetting, and boil for a 
least half an hour, (b) Heavy woolen clothing, silks, 
furs, stuffed bed-covers, beds, and other articles which 
cannot be treated with the zinc solution, should be 
hung in the room during fumigation, their surfaces 
thoroughly exposed, and pockets turned inside out. 
Afterward they should be hung in the open air, beaten 
and shaken. Pillows, beds, stuffed mattresses, uphol- 
stered furniture, etc., should be cut open, the contents 
spread out and thoroughly fumigated. Carpets are 
best fumigated on the floor, but should afterwards be 
removed to the open air and thoroughly beaten. 

Corpses, especially of persons that have died of any 
infectious or malignant disease, should be thoroughly 
washed with a zinc solution of double strength ; should 
then be wrapped in a sheet wet with the zinc solution, 
and buried at once. 



POISONS AND THEIR ANTIDOTES. 313 



CHAPTER 39. 

POISONS AND THEIR ANTIDOTES. 

/\ POISON may be defined as any substance capable 
i\ of producing within the animal or human body a 
noxious or deadly effect. This definition includes, of 
course, injurious chemical compounds of an inorganic 
nature, also certain vegetable products, and the venom 
of animals. Many poisonous matters produce local 
effects of irritation and pain, such as the strong acids 
and alkalies and corrosive mineral compounds ; others 
act remotely upon the body, that is, through absorption 
by the blood and consequent derangements of the nerv- 
ous system ; such are called narcotic or neurotic poisons, 
and include opium, aconite, alcohol, etc. All poisons 
in large quantities operate speedily when taken into 
the body ; though some are cumulative in their nature, 
that is, they may be taken in repeated doses each too 
small to produce alone serious effects, but by accumu- 
lating within the body they give rise to chronic de- 
rangements of increasing severity : of such poisons 
lead and arsenic are examples. 

In most severe cases of poisoning, the symptoms will 
be clearly marked and the attendant circumstances will 
likely indicate the nature of the poisonous substance 
used. Prompt measures for relief should be taken. 
As a rule, when it is found that a poison has been 
swallowed, the first thing to be done is to remove the 
contents of the stomach, thus preventing farther 
absorption of the poison. If vomiting has not 



Sl4 DOMESTIC SCIENCE. 

occurred, simple" emetics should be administered. 
Among common emetics, the wine of ipecacuanha is 
good ; give at least a tablespoonful in the case of an 
adult, less for children. In the absence of this, mix 
powdered mustard and salt in water — a teaspoonful of 
mustard and an equal amount of salt, the latter dis- 
solved and the former well mixed in a pint of warm 
water. A tablespoonful of powdered alum, with an 
equal quantity of molasses, honey, or sugar, well 
stirred in water, is a good emetic dose. Mechanical 
irritation in the throat, as by tickling with a feather or 
the finger, will often induce vomiting. As quickness 
of action is of great import, repeat the emetic doses 
at frequent intervals (every ten or fifteen minutes) till 
copious vomiting occurs ; then aid the operation by 
plentiful draughts of dilutent liquids, such as warm 
water, alone or with sugar ; mucilage of gum arable 
(do not use the prepared gum mucilage, it contains 
poisonous ingredients), watery infusions of slippery 
elm, or fiax-seed tea. A stomach pump, if at hand, 
may be used to good effect in cleansing the stomach. 

Another important step is to neutralize and thus 
render inert, as far as possible, the poison within the 
body, for this purpose certain antidotes should be 
given. ■ The object of the antidote is to produce 
insoluble compounds which will be secure against 
absorption till they can be removed from the body. 
Below are named some of the commonest poisons and 
the antidotes well suited to each case. 

Strong Mineral Acids, such as nitric acid (aqua- 
fortis), hydrochloric acid (muriatic), sulphuric acid 
(oil of vitriol). Administer alkalies, such as soda, 



POISONS AND THEIR ANTIDOTES. 315 

lime, whiting, magnesia, stirred in water. In the 
absence of these, take some plaster from the wall, 
crush fine, stir in milk, and administer ; soap dissolved 
in water is good. In any case, follow with dilutents. 

Organic Adds : — Oxalic acid is frequently taken by 
mistake, because of its resemblance to another house- 
hold chemical — Epsom salts. Antidotes for oxalic 
acid — magnesia, chalk, or even wall plaster mixed with 
water. Prussic acid may be taken as oil of bitter 
almonds, or potassium cyanide ; the effect is usually 
too rapid to admit of effectual antidotes, when possi- 
ble, however, give very dilute ammonia, or chlorine 
water, or let the dilute gases from such be inhaled. 
Cold water applied to the spine is beneficial. 

Strong Alkalies, such as ammonia, potash — as caus- 
tic potash, potash lye, pearlash, .potassium nitrate 
(saltpeter) ; soda, as soda lye, etc. Give freely dilute 
acids, such as vinegar, citric acid, or tartaric acid, in 
water ; these tend to neutralize the alkali. Give also 
large doses of oil, as olive oil, linseed oil, or castor 
oil ; the oils form soap vnth strong alkalies, and so 
delay their ill effects. 

Antimony compounds, as tartar emetic, wine of 
antimony, etc. Vomiting is of great importance. 
Give astringent infusions, as strong green tea ; let tea 
leaves be chewed and swallowed; infusion of oak- 
bark, nut galls, or tannin. 

Arseiiic: — Usually taken as white arsenic, Paris 
green, Scheele's green, cobalt powders ; and among 
patented preparations: Fowler's solution, and various 
mouse and rat poisons. Give abundance of milk and 
lyhite of eggs. The best antidote is the hydrated per- 



316 DOMESTIC SCIENCE. 

oxide of iron; to prepare: pour together solutions of 
perchloride of iron and dilute ammonia, both of which 
may be obtained at drug stores ; a brown precipitate 
forms in the mixture ; strain through linen ; mix the 
brown mass with water and administer freely. 

Copper salts ; as copper acetate (verdigris) often 
imbibed from unclean copper vessels used in cooking 
or pickling; copper sulphate (blue vitriol). Give 
freely of milk, white of eggs, and carbonate of soda. 

Iron ; as iron sulphate (green vitriol). Give carbon- 
ate of soda and plenty of mucilaginous drinks. 

Lead', as lead acetate (sugar of lead), lead carbon- 
ate (white lead), red lead, also from water that has 
been kept in leaden pipes or vessels. Give very dilute 
sulphuric acid, or Epsom salts, in water. Administer 
oil and mucilaginous drinks with emetics. In chronic 
cases of lead poisoning, as in " leading" from exposure 
to fumes of the metal, repeated doses of diluted sul- 
phuric acid, or of potassium iodide, may be recom- 
mended. 

Mercury : as mercuric chloride (corrosive sublimate), 
ammoniated mercury (white precipitate), mercuric 
oxide (red precipitate), murcuric sulphide (vermillion). 
Give white of Qgg in abundance, or flour mixed with 
water or milk, or soap and water. Avoid strong emetics 
or irritating substances. Use the stomach pump if 
possible. 

Silver:, as silver nitrate (lunar caustic). Give salt 
and water, then oil. 

Zinc: as zinc chloride (butter of zinc,) zinc sulphate 
(white vitriol). Zinc salts are themselves emetics; 



POISONS AND THEIR ANTIDOTES. * 317 

relieve the vomiting by dilutent drinks, and give 
sodium carbonate in water. 

PJwsj^horics, from matches and vermin poisons. 
Give magnesia, or chalk, in water; flour in water; 
follow with mucilaginous liquids in abundance. 

Certain Gases are sometimes breathed with toxic effect. 
For chlorine inhalation, let the sufferer cautiously 
breathe ammonia. In cases of poisoning from carbon 
dioxide, carbon monoxide (from fumes of coke or of 
burning charcoal), hydrogen sulphide, illuminating 
gas ; relieve the stupor by applying cold water to the 
head, — give stimulants, and establish artificial respira- 
tion. To effect this, take the patient in the fresh air, 
and, except in the severest weather, expose the face, 
neck, and chest; clear the throat of mucus by turning 
the patient face down wand with mouth open ; hold 
dilute ammonia to the nostrils. If respiration does 
not take place, put the patient face downward, then 
roll the body almost over and back again, regularly 
(about fifteen times a minute) : this causes alternate 
compression and expansion of the chest and favors the 
influx and escape of air. Rub the limbs upward, 
using considerable energy. 

Narcotic poisons : — as opium (gum opium, laudanum, 
paregoric, infusion of poppies, soothing syrup ; cholera 
mixtures; most patented "cordials"), digitalis, 
aconite, hemlock, belladonna ; stramonium. GivS 
emetics, or use stomach pump promptly. Keep the 
patient awake, in motion if possible ; dash cold water 
On head and shoulders, administer strong coffee or tea ; 
also vinegar, or lemon juice. Keep the limbs warm ; 
if necessary resort to artificial respiration. As con- 



318 DOMESTIC SCIENCE. 

sciousness returns, continue the use of coffee and give 
weak stimulants, such as wine or brandy in water. 

Strychnine and brucine (nux vomica) are somewhat 
allied to the foregoing, though these usually produce 
violent spasms. Cautiously administer chloroform or 
ether to quiet the spasms ; then give powdered charcoal 
in water (Walker). 

Irritant vegetable poisonf^, such as croton oil, and 
many essential oils and essences, are often swallowed 
with poisonous effect. Vomiting is likely to occur 
spontaneously ; if not, however, administer emetics 
without delay, aid vomiting by warm draughts, and 
follow with an efficient purgative. Give vinegar, 
lemon juice, or strong coffee. 

Poisonous meats, jish^ or cheese are sometimes eaten. 
Evacuate the stomach without delay by emetics and 
purgatives, and give good doses of vinegar and water. 
Hutchinson recommends that this treatment be followed 
by small doses of ether with a few drops of laudanum 
in sweetened water. 

Animal venom may be received from bites of mad 
dogs, and of snakes, and spiders, and the stings of 
insects. Wash the wound with dilute ammonia ; if on 
a limb, tie a bandage above the place of injury ; if pos- 
sible let the wound be freely sucked, the mouth being 
afterwards well rinsed with water. Moderate amounts 
of alcoholic stimulants may be given. In severe cases 
ammonia may be injected into the veins, — only a com- 
petent physician or surgeon should attempt this 
operation. As an extreme measure, the wound may 
be cauterized by the application of nitrate of silver, or 
by pressing the heated point of a small poker, or a 



POISONS AND THEIR ANTIDOTES. 319 

knitting needle, into the wound. In the case of 
insect stings, extract the sting if still in the wound : a 
pair of forceps will aid in this, or the barrel of a small 
key may be pressed around the sting. Apply to the 
wound a little dilute ammonia, or spirits of camphor, 
or moistened soda ; or in lack of these, earth, mixed 
into a mud with saliva. A cloth dipped into a weak 
aqueous solution of carbolic acid may be applied to the 
affected part. If symptoms of internal distress make 
their appearance, give cautiously four or five drops of 
carbolic acid in a wine glass of water. 

These are but a few of the commonest poisons ; the 
antidotes recommended are such as are likely to be of 
ready access. 



Page 23, twelfth and thirteenth lines, should read 
25,600 pounds or 12.8 tons. 

Same page, sixteenth and seventeenth lines, should 
read 30,000 pounds, or fully 15 tons. 

Page 43, table should read as follows : — 

BY WEIGHT. BY VOLUME. 

Oxygen 23.1 per cent, 20.9 

Nitrogen 76.9 " •• 79.1 



100. 100. 



INDEX. 



Air, Physical properties of - - 9 

Air, Impenetrability of - - 10 

Air, Weight of - - 12 

Air, Pressure of - - 14, 20 

Air-pump - - - 16 

Aneroid barometer - - 26 

Air, Composition of - - 33 

Air, Humidity of _ , _ 42 

Air, Permanency of - - 44 

Air of rooms - - 51 

Air, Contamination of - - 51-57 

Air supply for dwellings - . - 57 

Air of cellars - - - 58 

Aeration of blood - - 63 

Arsenical wall papers - - 78 

Anthracite - - 115 

Argand lamp _ . _ 133 

Animals, Water in - - 149 

Ammonia in water - - 176 

Albuminoid ammonia in water - 176 

Alum, for purifying water - - 195 

Alum waters - - 199 

Amyloid foods - - - 222 

Acids, Vegetable - - - 230 

Acid, Tartaric - - 230^ 

Acid, Citric - - - 230 

Acid, Malic - - 231 

Acid, Oxalic - - - 231 

Acid, Acetic - - 232 

Acid, Salicylic, as preservative - - 292 

Albuminoids in foods - - 237 

Albumen - - 237 

Antiseptics, as preservatives of food - 289 

Alcohol as an antiseptic - - 290 



322 INDEX . 

Ammonia as a detergent - - 298 

Antidotes to poisons • - - 313 

Barometer - - 24 

Barometer, Siphon - - 24 

Barometer, Wheel - . - 25 

Barometer, Aneroid - - 26 

Blood, Aeration of - - 63 

Bituminous coal - - 115 

Blowpipe - - 131 

Burners, (gas) - - 139 

Burners, (ventilator) - - 140 

Boiling of water - - 188 

Blood, Clotting of - - 289 

Bulbs — onions - - 248 

Beets - - 249 

Bran — of grains - - 255 

Bread - - 259 

Bread — new and stale - - 260 

Baking powders - - 260 

Barley as food - - 262 

Buckwheat as food - - 264 

Beef- tea - - 267 

"Boiling" of meat - - 266 

Broiling of meat - - 269 

Butter - - 275 

Butter, .Artificial - - 275 

Bacteria - - 286 

Boric acid, as preservative - 291 

Bleaching - - 299 

Bleaching by chlorine - - 300 

Bleaching by sulphur-dioxide - - 302 

Bleaching powder - 306 

Carbon-dioxide in air - - 38 

Chlorophyle - - 47 

Carboniferous age, Atmosphere during - 48 

Cellars, 111 effects of - - 58 

Consumption induced by impure air - 64 

Coal-miners, Mortality among - 71 

Currents, Ventilating - - 83 

Compensation pendulum, (gridiron) - 95 

Coigjpensation pendulum (mercurial bob) - 95 

Celsius thermometer - - 98 



INDEX. 32S 

Communication of heat - - 101 

Conduction of heat - - 101 

Convection of heat - - 103 

Coal, Varieties of - - 114 

Cannel coal - - 114 

Charcoal, as fuel - - 116 

Coke - - - 116 

Candle ilame - - 130 

Coal-gas as fuel - - 116 

Coal-gas as illuminant - - 138 

Crystals of ice - - 154 

Chlorine in water - - 178 

Condenser, Liebig's - - 191 

Carbonated waters - - 197 

Calcium waters - - 198 

Chalybeate waters - - 198 

Composition of water - - 202 

Cookery, Purposes of - - 213 

Carbonaceous foods - - 222 

Citric acid - - 230 

Casein - - - 242 

Carrots - - 249 

Cabbage - - - 250 

Cheese - - 277 

Condiments - - - 278 

Coffee - - 283 

Cocoa and chocolate - - 283 

Creosote as an antiseptic - - 291 

Cleansing agents - - 293 

Chlorine as bleaching agent - 300 

Chlorine as disinfectant - - 306 

Charcoal — its absorbing power - 304 

Chloride of lime - - 306 

Carbolic acid, (disinfectant) - 307 

Copperas, (disinfectant) - - 308 

Corrosive sublimate, (disinfectant) - 309 

Dropping tube - - 31 

Diffusion of gases - - 34 

Drying power of air - - 42 

Dysentery — induced by impure air - 65 

Dysentery — induced by impure water - 179 

Dust in the air - - 70 

Dust, Poisonous - - 73 



324 INDEX. 

Dust, Household - - 75 

Double case stove - - 123 

Dead sea, Water of - - 167, 200 

Distillation of water - - 189 

Drying, as preservative - - 289 

Detergents - - - 293 

Disinfectants - - 304 

Deodorizers - - - 306 

Disinfection, Directions for - 310 

Esquimaux, Ventilation among the - 66 

Exhaust fan in ventilating - 89 

Effects of heat - - - 92 

Expansion of solids by heat - 93 

Expansion of liquids and gases by heat - 96 

Electric lamps, (arc) - - 140 

Electric lamps, (incandescent) - - 141 

Efflorescence - - 145 

Electrolysis of water - - 203 

Eggs as food - - 271 

Emetics, in poisioning cases - - 313 

Force-pump - - 29 

Fungi, Exhalations of - - 47 

Fan in ventilating - - 89 

Fahrenheit thermometer - - 97 

Fuels - - - 109 

Flame - - - 111 

Fireplace, Open - - 119 

Flashing point of oils - - 137 

Fire-test point of oils - - 137 

Freezing of water - - 153 

Free ammonia in water - - 176 

Filtration of water - - 192 

Filter, Domestic - - 192 

Filter, Pasteur- Chamberland - - 194 

Foods, Nature of - - 207 

Foods, Classification of - - 208 

Foods, Necessity for several kinds - 208 

Foods, Flesh - - 209 

Foods, Mineral Ingredients of - 215 

Foods, Organic ingredients of - - 222 

Foods, Carbonaceous - - 222 



INDEX. 325 

Foods, Nitrogenous - - 237 

Foods, Auxilliary,' - - 278 

Food-stuffs, Preservation of - - 286 

Fats in food - - 232 

Fats, Phosphorized - - 233 

Fats in plants - - 234 

Fats in animal matters - - 234 

Fibrin - - - 238 

Fibres of meat _ - _ 239 

Fruits, as food - - 252 

Flour as food - . _ 255 

Flesh as food - - 265 

Fish as food - - - 266 

Frying of meat - - 269 

Frying kettle - - - 270 

Freezing as preservative - - 287 

Gillis system of ventilating - - 88 

Gas coal, as fuel - - 116 

Gas coal, as illuminant - - 136 

Gasoline - - 116 

Gas, Water - - 139 

Goitre - - 170 

Gasses in water - - 171 

Glucose - - 227 

Gums in food - - 228 

Gelatin - - 240 

Gluten - - - 243 

Grains, as food - - 254 

Grilling of meat - - 269 

Green vitriol (disinfectant) - - 308 

Humidity of air - - 42 

Human respiration, effects on air - 55 

Household dust - - 75 

Heat, Some effects of - - 92 

Heat, Communication of - - 101 

Heat, Conduction of - - 101 

Heat, Convection of - - 103 

Heat, Radiation of - - 104 

Heat, Latent _ _ _ io5 

Heat, Specific - - 106 

House warming - - 119 

Hollow-wick lamp - - 13 



S26 



INDEX. 



Hardness of water - - i68 

Hydrogen - - 204 

Hermetic sealing as preservative - - 287 

Heat, (agent in disinfecting) - 310 

Impenetrability of air - - - lo 

111 effects of impure air - - 61 

Inlets for air to room - - 90 

Illuminants - - 137 

Ice crystals - - - 154 

Iron in food - - 219 

Indian corn as food - - 262 

Impure soaps - - 297 

Iron sulphate (disinfectant) - - 308 

Kerosene _ _ _ 137 

Lifting pump - - - 28 

Lyman's ventilator - - 84 

Latent heat - - - 105 

Lignite - - - 114 

Lighting - - - 129 

Lamp, Simple _ _ . 132 

" Argand - - - 133 

" Student's . - - - 134 

" Hollow wick - - - 135 

Living organisms in water - - 181 

Liebig condenser _ _ _ 191 

Lime in food - - 218 

Leaves as food _ _ _ 250 

Lemon juice - - 279 

Lime (absorbent) - - - 304 

Lime (in disinfectants) - - 309 

Lead chloride (disinfectant) - - 309 

Magdeburg hemispheres - - 18 

Morbid effects of impure air - 63 

Mental powers affected by impure air - 67 

Mines, Ventilation of - 84 

Mechanical aids to ventilation - - 89 

Matches - - 117 

Mineral, Water in - - 144 

Marah, Waters of - - 196 

Mineral waters - - 197 

Mineral ingredients of food - 214 



INDEX, 327 

Malic acid - - 231 

Maize as food - - 262 

Milk - - 273 

Margarine - - - 275 

Marine soap ' t - 296 

Mercuric chloride (disinfectant) - - 309 

Nitrogen in air - - 35 

Nitrogenous ingredients of food - 237 

Neurotic poisons - - 313 

Narcotic poisons - - 313 

Oxygen in the air - - 37 

Organs of respiration - - 61 

Open fire place - - 119 

Organic impurities in water - 176 

Oxy- hydrogen flame - - 205 

Organic ingredients of foods - 222 

Oxalic acid - - 231 

Oils in food - . - 232 

Oils, fixed and essential - - 233 

Oils, Essential - 279 

Oils in plants - - 234 

Olein - - 235 

Onions as food - - 248 

Oats as food - - 263 

Oleomargarine - - 275 

Oil, as a preservative - - 291 

Physical properties of air - - 9 

Pressure of the air - - 14-20 

Pump, Air - ^ - - 16 

Pump, Lifting - - 58 

Puimp, Force - - - 29 

Pipette - - 31 

Permanency of the atmosphere - - 44 

Poisonous dust - - 73 

Poisonous wall papers - - 78 

Pendulum, compensation - - 95 

Production of heat - - 109 

Plants, Water in - - 146 

Properties of water - - 151 

Pasteur — Chamberlain filters " 194 

Phosphorus in foods - - 220 



328 INDEX. 

Penicillium, a mold - - 220 

Pectin - - 231 

Phosphorized fats - - 233 

Palmitin - - - 235 

Proteids in food - - 237 

Potatoes - - - 245 

Potatoes, Cooking of - - 246 

Parsnips - - - 249 

Pickles _ _ _ 279 

Preservation of food - - 286 

Poisions and their antidotes - - 313 

Poisons, (narcotic) - - 313, 317 

Poisoning, Symptoms of - - 313 

Poison, (mineral acids) - - 314 

Poison, (organic acids) - - 315 

Poison, (alkalies) - - 315 

Poison, (antimony) - - 315 

Poison, (arsenic) - - - 315 

Poison, (copper) - - 316 

Poison, (iron) - - - 316 

Poison, (lead) - - 316 

Poison, (mercury) - - - 316 

Poison, (silver) : : 316 

Poison, (zinc) - - 316 

Poison, (phosphorus) - - 316 

Poison, (gases) - - 317 

Poison, (strychnine, etc.) - - 317 

Poison, (irritant vegetable) - - 318 

Poison, (meats, fish etc) - - 318 

Poison, (animal) - - - 318 

Respiration, Effects of, on air • - - 55 

Respiration, Organs of - - 61 

Respiratory organs. Ciliated passages of - 74 

Registers, Ventilating - - 88 

Radiation of heat - - 104 

Rain water - - 156 

River water - - - 162 

Radishes - - 250 

Rye as food - - - 262 

Rice as food - - 264 

Roasting of meat _ . - 268 

Siphon barometer - - *" 24 



INDEX. 



329 



Storm -glass 

Siphon 

Scrofula, induced by impure air 

Scheele's green on wall paper 

Schweinfurth green 

Specific heat 

Semi-bituminous coal 

Stoves 

Steam warming 

Student's Lamp 

Sources of water 

Springs 

Springs, Intermittent 

Springs, Thermal 

Solids dissolved in water 

Solutions 

Salt Lake, Water of 

Soap, Effects of hard water upon 

Soda water 

Solid impurities in water 

Sulphur waters 

Saline waters 

Salt in food 

Salt in the human body 

Salt, Necessity for 

Stearine 

Sulphur in foods 

Starch in foods 

Starch in plants 

Sugar in food 

Sugar — Saccharose 

Sugar— Glucose 

Salads 

Seeds for food 

Seething of meat 

Spices, as condiments 

Salt, as an antiseptic 

Soap, 

Soaps, Hard and soft 

Soap, Marine 

Soap, Impure 

Saponification 

12 



27 
31 
63 
79 

79 
106 
115 
122 
126 
133 
156 
157 
160 
201 
166 
164 
167,199 
168 
174 
180 
197 
199 
215 
215 
216 
235 
220 
222 
224 
226 
226 
227 
251 
252 
266 
280 
290 
294 
295 
296 
297 
295 



330 • INDEX. 

Sulphur dioxide in bleaching - 302 

Sulphur dioxide in disinf ectinj^ - - 307 

Tabernacle, Salt Lake City, Weight of air in - 13 

Tabernacle, Air pressure on roof - 23 

Tuberculosis — Induce by impured air - 64 

Tonsilitis — Induced by impure air - 63 

Tin miners. Mortality among - - 72 

Thermometer - - 97 

Thermometer, Fahrenheit - - 97 

Thermometer, Celsius - - 98 

Tests for potable water - - 183 

Tannin, for purifying water - 195 

Thermal springs - - 201 

Tartaric acid - - 230 

Tubers — Potatoes - - 245 

Turnips - - 249 

Tea - - - 281 

Thymol (disinfectant) - - 308 

Uses of water - - - 151 

Vapor in air - - 41 

Ventilation - - - 81 

Ventilating currents - - 83 

Ventilator, (Lyman's) - - 84 

Ventilation by Gillis system - 88 

Ventilation by mechanical means - - 89 

Vapor gas' - - 139 

Ventilator-burners - - 140 

Vegetable gums - - 228 

Vegetable acids - - 230 

Vegetable jelly - - 231 

Vegetable food stuffs - - - 245 

Vinegar - - 278 

Vitriol, Green, (disinfectant) - - 308 

Weight of air . . 12 

Wheel barometer - - 25 

Watery vapor in air - - 41 

Woods, as fuels - - 113 

Warm air, (for house warming) - 125 

Warm water, (for house warming - - 127 

Water gas - - 139 



INDEX. 331 

Water — its occurrence - - 144 

Water in minerals - - 144 

Water in plants - - 146 

Water in animals - - 149 

Water, Rain - - 156 

Water of rivers - - 162 

Water of wells - - 163 

Water, a solvent - - 164 

Water, a solvent for gases - - 171 

Water, Organic impurities of - 176 

Water, Solid impurities in - - iso 

Water, Living organisms in - 181 

Water, Tests for purity of - - 134 

Water, Color of - - 184 

Water, Clearness of - - i84 

Water, Odor of - - 185 

Water, Taste of - - I86 

Water, Purification of - - 188 

Water, Boiling of - - 188 

Water, Distillation of - - 189 

Water, Mineral - - 197 

Water, Composition of - - 202 

Waters of Marah - ^ - 196 

Waters, Carbonated - - 197 

Waters, Sulphur - - 197 

Waters, Calcium - - 198 

Waters, Chalybeate - - 198 

Waters, Alum - - I99 

Waters, Saline - - 199 

Water of Great Salt Lake - 167, 199 

Water of Dead Sea - - 167, 200 

Wheat as food - - 254 

Water bath - - - 267 

Washing compounds - - 297 

Yeast, in bread making - - 257 

Yeast, Structure of - - 257 

Yeast, Compressed - - 258 

Zinc Salts, (dssinfectants) - - 309 

Zinc sulphate, (disinfectant) - - 309 

Zinc chloride (disinfectant) - - 309 



PUBLISHERS' NOTE. 



We respectfully offer a brief explanation regarding the 
illustrative cuts that appear in this little work. Photo- 
types were made for the book, but when all else was 
in readiness for the compositors, these were found to 
be of wrong size ; they were therefore discarded, and, 
under press of time, a substitute was sought in the 
free-hand platae appearing in the text. We are well 
aware of their many imperfections ; but we venture to 
present theni as they are rather than delay the issuance 
of the book during the time requisite for the prepara- 
tion of other engravings. 



i vikk 



